Comparative Review of 15 Closed Headphones, 2 Canalphones
and a Discussion on Reviews and Frequency Graphs
by Tao Tao
Line up: AKG K 271 Studio / K 81 DJ / K 181 DJ, Audio Technica ATH-A900 / ATH-FC7,
Beyerdynamic DT 250-80 / DT 250-250 / DT 660 / DT 770-80 Pro / DT 831, Sennheiser HD 25-1 /
HD 201 / HD 280 Pro, Sony V6, Ultrasone HFI 650 Trackmaster, Etymotic ER-4P / ER-4S, Shure
E3
Latest update: December 12th 2006
1. Introduction
Closed headphones brought me into headphone listening and I think that due to various
reasons they can be a reasonable gateway to the world of headphones for most people. This
review will discuss and review several closed headphones as well as two popular canalphone
choices.
The second and third part of this paper contain some of my findings on headphone-related
topics, which I hope can be an useful guideline to the unseasoned (chapter three) as well as an
entertaining analysis to the more experienced headphone enthusiast (chapter four).
1
1.1 Table of Contents1
I admire people who make it a virtue to write reviews that are succinct and hit the point
without the use of big words or complicated sentences. As you can see from the numbers of
pages, the first criteria failed me and putting the lack of big words into a positive light would
be as close to the truth as complimenting a bankrupt audiophile for his ascetic lifestyle.
Nevertheless, I still hope you can benefit from this review.
There is a comprehensive list of audiophile terminologies following this link (PDF-file)2,
which can be consulted if certain terminologies are unclear.
1. INTRODUCTION .................................................................................................... 1
1.1 Table of Contents ............................................................................................................... 2
1.2 Personal Remarks .............................................................................................................. 4
1.3 Background and Additional Information ........................................................................ 5
Personal Biases ....................................................................................................................... 5
Testing Methodology ............................................................................................................. 5
Music Used ............................................................................................................................. 5
Associated Equipment ............................................................................................................ 5
Change Log ............................................................................................................................ 6
2. REVIEW ................................................................................................................. 7
2.1 Why ‘Closed’ to begin with? ............................................................................................. 7
2.2 General Review ................................................................................................................... 8
Sennheiser HD 201 ................................................................................................................. 8
Audio Technica ATH-FC7 ..................................................................................................... 9
AKG K 81 DJ ....................................................................................................................... 10
Sony V6 ................................................................................................................................ 11
Sennheiser HD 25-1 ............................................................................................................. 13
Ultrasone HFI 650 Trackmaster ........................................................................................... 15
Beyerdynamic DT 250-250 .................................................................................................. 17
Beyerdynamic DT 250-80 .................................................................................................... 19
Sennheiser HD 280 Pro ........................................................................................................ 21
Beyerdynamic DT 660 ......................................................................................................... 22
AKG K 181 DJ ..................................................................................................................... 24
Beyerdynamic DT 770-80 Pro ............................................................................................. 25
Beyerdynamic DT 831 ......................................................................................................... 27
Audio Technica A900 .......................................................................................................... 28
AKG K271 Studio ................................................................................................................ 30
Etymotic ER-4P / Etymotic ER-4S ...................................................................................... 31
Shure E3 ............................................................................................................................... 32
2.3 In-Detail Review ............................................................................................................... 34
1
2
You can navigate through this review using Acrobat Reader’s bookmarks
Compiled by Head-Fi members ServingInEcuador and John_Jcb.
2
Sennheiser HD 201 ............................................................................................................... 34
Sony V6 ................................................................................................................................ 36
AKG K 81 DJ ....................................................................................................................... 38
Ultrasone HFI 650 Trackmaster ........................................................................................... 39
Beyerdynamic DT 250-250 .................................................................................................. 41
Beyerdynamic DT 660 ......................................................................................................... 43
Beyerdynamic DT 770-80 Pro ............................................................................................. 45
Beyerdynamic DT 831 ......................................................................................................... 48
Audio Technica A900 .......................................................................................................... 50
AKG K271 Studio ................................................................................................................ 52
2.4 Conclusion ......................................................................................................................... 54
3. HEADPHONE-RELATED TOPICS ...................................................................... 60
3.1 Canalphones vs. Headphones .......................................................................................... 60
Isolation ................................................................................................................................ 60
“Canalphones are harmful to ears” ....................................................................................... 60
Canalphones require maintenance ........................................................................................ 60
Size / Portability ................................................................................................................... 61
Battery Drain ........................................................................................................................ 61
Insertion / Wear .................................................................................................................... 61
Sound quality........................................................................................................................ 62
Why the perception of canalphones might differ from user to user ..................................... 63
Conclusion ............................................................................................................................ 63
3.2 Headphones: Cheaper Alternatives ................................................................................ 63
Open Headphones ................................................................................................................ 63
Closed Headphones .............................................................................................................. 64
Earphones / Entry-level canalphones ................................................................................... 64
Conclusion ............................................................................................................................ 65
3.3 Amped vs. Unamped / Portable Headphone Amplifiers ............................................... 65
“Easy to drive” / “Hard to drive” ......................................................................................... 65
Volume Testings with Ipod .................................................................................................. 66
Is an amp really necessary? .................................................................................................. 67
In what areas does an amp improve the sound quality? ....................................................... 67
What do I lose? ..................................................................................................................... 67
What’s a reasonable spending limit? .................................................................................... 68
3.4 Headphone Cable and Misc ............................................................................................. 68
Headphone plug: Angled vs. Straight .................................................................................. 68
Cable: Coiled vs. Straight..................................................................................................... 68
Cable Upgrades .................................................................................................................... 68
Cable Upgrade: Sennheiser HD 25-1 ................................................................................... 69
Cable Upgrade: Other headphones ....................................................................................... 69
Serial Resistance Adapters (e.g. 120 Ohm or 75 Ohm) ....................................................... 70
Damping factor ..................................................................................................................... 70
4. FREQUENCY GRAPHS AND REVIEWERS SCRUTINIZED ............................... 72
4.1 Frequency Graphs ............................................................................................................ 72
3
FG Basics ............................................................................................................................. 72
Measuring FG ....................................................................................................................... 73
How to read and use FG ....................................................................................................... 74
Conclusion ............................................................................................................................ 74
4.2 Reviews and Reviewers .................................................................................................... 75
Psychological Influences ...................................................................................................... 75
Psychoacoustical Influences ................................................................................................ 76
Other possible Influences ..................................................................................................... 80
Conclusion ............................................................................................................................ 82
4.3 Conclusion ......................................................................................................................... 83
5. APPENDIX ........................................................................................................... 83
Further Reading ..................................................................................................................... 83
Headphone related ................................................................................................................ 83
Hearing related ..................................................................................................................... 84
Misc ...................................................................................................................................... 85
1.2 Personal Remarks
There are quite a few reasons why reviews and reviewers should be watched like a hawk and I
will try to discuss this in length in chapter four. In an ideal world, reviews should only
provide incentives as to which headphones should be considered more closely. Blind
purchases always require a leap of faith and reviews can only manage to make it a welleducated one at most. However, it is often difficult to arrange for an audition under controlled
conditions, and headphone meets or quick auditions at local stores are not entirely reliable
from my experience. Some headphones come from overseas and may not be available for
audition. Such are the trade-offs of an imperfect world so that the consumer often has to rely
on reviews and impressions to make his final decision. While a review cannot be a
replacement for an audition, the concept thereof should not be dismissed due to the occasional
lack of meaningful alternatives. Yet in this case, an open and critical mind is the most
important prerequisite when reading a review. In the end a review, as professional, wellformulated or substantiated as it may be, is but an opinion.
Acknowledgements
Thanks to Head-Fi member lukaas for lending me his Beyerdynamic DT 250-250 for an
extended period of time. Thanks to Head-Fi members ServingInEcuador and John_Jcb for
providing an extensive list of audiophile terminologies to the public. Thanks to Head-Fi
member publius for providing me with a highly capable and self-programmed EQ plug-in for
foobar. Thanks to Head-Fi member and good friend JaZZ for lending me the Talisman T-3H
headphone amp and some headphones. Many thanks to Head-Fi member Halcyon for helping
me write chapter 4 in this review. Thanks to the administrator and other people that keep
Head-Fi running.
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1.3 Background and Additional Information
Personal Biases
My baseline headphone is the Sennheiser HD 650 with an upgraded headphone cable. I like
its somewhat dark and organic but nonetheless focused and resolving sound. It might not be
the most transparent headphone unless driven from the more expensive headphones amps and
many people consider it “veiled”, which is arguable, but I’m neither a fan of having details
shoved down my throat nor do I fancy an overly bright treble. I like a strong bass and if I had
to make a choice I would sacrifice bass definition in exchange for slam and impact. I prefer
the down-to-earth listening experience of a dynamic headphone to the more ethereal sound of
electrostatic headphones. Overall, coherency is what I consider most important. The HD 650
has a prominent lower midrange and I tend to criticize headphones for their lack thereof just
as the HD 650’s more subdued treble level may have sensitized me towards brighter
headphones. Finally, I’d like to add that even though the HD 650 is my headphone of choice,
it is far from being ideal in all individual disciplines. It’s only that the alternatives are either
too expensive or have distinctive flaws that I cannot live with.
Testing Methodology
When reviewing the headphones, I used both short-term (seconds, minutes) as well as longterm (days) comparisons over a period of two to three months since some differences were
more apparent in long term, others more in short-term comparisons. I took the headphones
with me on the bus, to the library, listened to them at home, in the mornings, in the evenings,
etc. I tried listening to the headphones at various volume levels using a representative
selection of music. Some things I paid attention to include: following each instrument
throughout a piece and at other instances concentrating on the big picture. I gave high priority
to how the headphones handled human voices, how realistically they were portrayed. I tried to
pay attention to micro-detailing meaning whether I could hear the fingers moving up the fret
board but also macro-detailing that is how I easily I could discern the various instruments
from each other. It was also important to me how effortless the music sounded, how easily I
could move between various layers of music and how much effort it was to pick out
individual details Both micro- and macro-dynamics were important to me and I used different
recordings to highlight these traits. I also liked drums for testing frequency extremes because
of its bass kick and the cymbals for the treble extremes. But most importantly, I liked to
simply sit back, savor the music and observe how much enjoyment I could draw from it.
Music Used
Due to the vast amount of time I had for this review (three months), I went through big parts
of my music collection including assorted albums of jazz, classical music, all sorts of
electronica, pop, rock and hip hop (in this order). My musical preferences are jazz, classical
music, electronica and pop music.
Associated Equipment

Sources: Custom CD player3 / E-MU 1212M soundcard / European Ipod 4th
Generation / Sony D-465 Discman / Philips AZ6831
3
Although it is difficult to provide a reference on the quality of this player, I can guarantee that anything but the
source to be the bottleneck in this review.
5



Amps: Talisman T-3H / A.N.T. Ruby prototype / Sonic Impact T amp (AKG K1000) /
ASL MG Head MKII / Emmeline SR-71 / Porta Corda MKI (modded) / Corda HA-2
MKII
Interconnects: Custom interconnects (copper conductor, Copper WBT Nextgen) / NW
Enterprise Music Timbre / Oehlbach mini-to-mini
Other headphones used: Sennheiser HD 650 with Silver Dragon cable (reference) /
AKG K1000 / Grado SR-225 / Koss KSC-35 / Shure E2 / Shure E5
Change Log
Excluding small changes or grammar / language corrections.
8/7/05
-
2.4 Conclusion text added
3.3 New chapter ‘What’s a reasonable spending limit?’
3/10/05
-
Review title and Chapter 4 title revised
1.2 ‘Personal Remarks’ section revised
1.3 ‘Updates History’ section added
2.2 Sennheiser HD 201 review and pictures added
2.2 Beyerdynamic DT 831 review and pictures added
2.3 Sennheiser HD 201 in-detail review added
2.3 Beyerdynamic DT 831 in-detail review added
2.4 Diagrams and tables revised
2.4 ‘Recommended Applications (Gaming, Movies, DJ, Mixing,
Portable, Semi-Portable, Home)’ section added
2.4 ‘Concluding Thoughts’ section added
3.3 Ipod volume readings for HD 201 and DT 831 added
3.4 ‘Serial Impedance Adapters’ section added
4.2 ‘Conclusion’ section edited
4.3 ‘Conclusion’ revised
3.4 ‘Damping factor’ section added
4.2 ‘Amateur vs. Professional Reviews’ sub-section added
4.2 ‘Lack of Negative Reviews’ sub-section added
2.2 AKG K 81 review added
2.3 AKG K 81 in-detail review added
2.2 Audio Technica ATH-FC7 review added
2.2 AKG K 181 review added
4.2 Portability vs. sound quality diagram revised and updated
2.2, 2.3 DT 250-250 channel imbalance issues
3.1 “Why the perception of canalphones might differ from user to user”
2.4 Conclusion revised due to inclusion of new headphones
3/15/06
12/12/06
-
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2. Review
Before we get started, I can only emphasize again how important it is to audition headphones
personally especially since I did not intend to make this an affectedly objective review. Some
issues are more subjective than others. Listening fatigue and perception of harshness for
instance can vary strongly from person to person.
All diagrams in this review are highly simplified and can only act as a rough guideline. 4
As for the headphones tested, they were selected based on recommendations from the Head-Fi
forum. All the headphones in this review have their following and I can say with confidence
that you can’t really go wrong with either of them. If you want to listen to some bad
headphone specimens, pick up a pair of Sony MDR V-700, some Pioneer DJ headphones or a
pair of - not necessarily bad - but certainly overpriced Bose headphones.
2.1 Why ‘Closed’ to begin with?
Making a relatively broad generalization: Open headphones usually sound better. Or more
precisely: They usually have a bigger potential to sound better than closed ones. Without
going into the technical details, if I had a hundred or two hundred dollars to spend on a single
headphone to achieve maximum sound quality, I’d be better off buying something along the
lines of a Sennheiser HD 600, Beyerdynamic DT880, Grado SR-225 and the likes. However,
you have to consider that these more sophisticated headphones may require an amp. To give
another example: The Sennheiser PX100, a great-sounding open headphone for $40, sounds
better than its slightly more expensive closed counterpart, the PX200. While there certainly
are high-end headphones with a closed design such as the Audio Technica W2002, Audio
Technica L3000, Sony CD3000 or the out-of-production Sony R10, these are clearly
exceptions rather than the rule.
Closed headphones can have certain advantages that will make the sound quality trade-off
worthwhile. First of all, closed headphones do not leak sound and some provide isolation to a
certain degree, which makes the listener very much independent from his listening
environment. Secondly, many closed headphones tend to have the portable aspect embodied
in their design, which will be of further discussion at a later point in this review. And since
some closed headphones are not designed for home listening, they are often more efficient
and can already sound good out of the average mp3 player. Some closed headphones such as
the Sennheiser HD 25-1 or HD 280 Pro are derived from studio applications, which implies a
solid build quality that comes in very handy for heavy-duty portable usage.
On the other hand, isolation goes hand in hand with less comfort. Closed headphones are
often more sweat-inducing, too.
It needs to be pointed out again that these are all broad generalizations. For instance, the
Audio Technica A900 can sound better than the highly-acclaimed Sennheiser HD 600 given
I included them mainly because they look nice. Most of all, don’t just go for the overall area because I did not
care for a fair weighting of the scaling. For a fair diagram, the sound quality aspect should have been more
emphasised.
4
7
poor amplification and a weak source such as cheap mp3 player. A closer examination is
therefore necessary.
2.2 General Review
Sennheiser HD 2015
Retail price6: $20
Type: Circumaural
Cable Length and Type: 3m, straight
The Sennheiser HD 201 is a very capable closed headphone and peerless for the price asked.
My initial excitement over this aggressively-priced headphone has settled down a bit mainly
due to a few flaws in the practical domain.
The sound is fairly neutral with good treble, a clean midrange and little weak but very tight
bass. The soundstage is surprisingly good and both transparency and resolution exceeded my
expectations. I first tried the HD 201 from my home rig with a home CD player and a $300
tube amp and really liked what I was hearing. However, things changed for the worse when I
took the HD 201 for a ride on the bus.
Due to the HD 201’s relative inefficiency, lack of good isolation, long and easily kinked
cable, and somewhat weak bass output, I don’t find it to be the ideal companion for heavy5
6
Added on March 10th
Most retail prices are based on prices offered by Head-Fi sponsors as of August 2005.
8
duty commuting or other applications where loud ambient noise is present. Your portable
player needs to have a fairly strong headphone out in order for the HD 201 to reach satisfying
volume levels and not to sound boring.
Considering its more portable design and use of cheaper materials, the comfort is surprisingly
good although long-term comfort tends to be compromised due to the relatively small ear
cups and cheap cushioning. Hence, I don’t think it’s not the ideal library or office headphone
either although your mileage may vary here.
But let’s face it: For $20 I definitely expected drawbacks and it’s a welcome surprise to find
them more in the areas of practicability rather than sound. There’s a plethora of headphones
on the market with high functionality but only a few with emphasis on good sound. If you can
live with the lean bass and all the practical considerations in mind - of which there are quite a
few - the HD 201 is an extremely solid performer. For the price asked, you’ll be hard pressed
to find a better sounding closed headphone.
Audio Technica ATH-FC7
Retail price: $60
Type: Supraaural
Cable Length and Type: straight, 1.5m
The ATH-FC7 is a headphone priced in the neighbourhood of the AKG K81 and Sony V6 and
could be a worthwhile choice if weight and size are your most important criteria.
The FC7 has its strong suit in the domain of portability. Being small and pretty lightweight
without a considerable clamping force, it’s also fairly comfortable to wear compared to other
closed headphones. The isolation, however, is rather lacking and so is the sound quality. More
on that later. I found the build quality to be acceptable and the ATH FC7 does look its part –
hardly any geek factor to speak of. The efficiency is also very good and an amp is not
necessary. Another plus is that it can be folded into a small package.
So far it seems to be a decent choice. The only, and one might argue, rather crucial flaw about
this headphone is that it doesn’t really sound good. Admittedly I’m exaggerating here but the
FC7 just doesn’t stand a chance against outings such as the AKG K81 or even Sennheiser HD
201, except for bass quantity in the latter case. It has a boomy bass (not overpowering, just
boomy), uninvolving midrange, dull treble and dismal resolution; somewhat similar to
listening to music through a pillow. I don’t want to go into issues like soundstage, timbre and
other characteristics since even the basics aren’t covered. It is still much better than the Sony
MDR V300 however.
As already mentioned in the beginning, the FC7 has its strength mainly from a portable
perspective. However, if you’re looking for a portable headphone in this price range and
willing to sacrifice a bit of looks and comfort, I’d strongly suggest taking a look at the AKG
K81 instead.
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AKG K 81 DJ
Retail price: $60
Type: Supraaural
Cable Length and Type: straight, 3m
The recently released AKG K81 has caused quite a stir in the forums and for once maybe
even rightly so. This is an excellent headphone however you look at it. Although it might not
say much, I feel the need to compare the AKG K81 to the HD 25-1 because it is that good.
But first things first. From a portable perspective, the K81 has similar merits as the HD 25-1 my reference closed, portable headphone. It is even lighter and arguably offers better comfort
than the Sennheiser headphone albeit still not outstanding due to the supraaural design. The
isolation is not quite as good but in exchange the K81 can be folded into a small package.
Efficiency is very good and the profile is fairly low. I wouldn’t call it pretty - no headphone is
when worn on the street - but it comes close. On the downside, the cable is too long7 and the
headband isn’t cushioned. The K81 can be comfortable worn around the neck and doesn’t
really mind being thrown around or squished into my messenger mindlessly.
As far as sound quality is concerned, the K81 is outstanding considering its price and closed
nature. Starting with its biggest flaw, I find the bass to be overpowering and almost boomy.
While the K81 certainly becomes a quite impactful headphone in this way, I often find it
necessary to tone down the bass using my Ipod’s eq. The bass balance just errs too much
towards "overbearing", which is a nice-to-have when I listen to pop, vocal-laden music,
electronica, some types or rock but it becomes a major nuisance when I try to enjoy a jazz trio
or a philharmonic orchestra (think Mahler). The K81's bass probably misses all audiophile
standards by a mile. That usually doesn't concern me when on the go as "bass" plus "portable"
usually equals fun for me, but it's really the bass balance in relation to the midrange where the
problem lies. Bill Evans' piano, for example, gets completely drowned by LaFaro’s bass.
The midrange of the K81 is very typical of the AKG house sound, meaning it is very neutral
with excellent clarity and good resolution. The treble lacks the sparkle of a HD 25-1 but
fortunately also the HD 25’s annoying sibilance with certain tracks. With high hats the K81
sometimes sounds a tad dull but I’m being picky here. Overall, this is a nicely balanced
headphone once you disregard bass-heavy music. Focusing on the K81’s other characteristics,
the soundstage is ok given its supraaural nature and I have already mentioned its nice
detailing.
I think the K81 is a truly outstanding product and at its price point pretty much peerless for a
portable, closed headphone. The only field where the likes of Sennheiser PX200, AT ATHFC7, etc. have an advantage is portability and comfort but the discrepancy in isolation and
especially sound quality over those featherweight closed headphones is huge. Besides, the
K81 is in my opinion definitely small and portable enough for most needs. I’ve only managed
to persuade two people to buy the HD 25-1 in a two-years span, but I have already convinced
three people to buy the K81 in four months time. I highly recommend this headphone because
never has great, portable sound been so cheap.
7
I’m using a Sumajin Smartwrap with great results.
10
Sony V6
Price: $70
Used: around $50
Type: Circumaural
Cable Length and Type8: 3m, coiled
The Sony V6 is the second least expensive headphone in this review and as such my
expectation were not very high.
Due to its ability to be folded, the V6 can be easily stored in bags without taking up too much
space. Comfort is not too bad although listeners with big ears may find the ear cups to be too
small and the pleather pads are rather sweat-inducing, too. Another problem I have found is
that hanging the headphone around the neck proved to be more cumbersome than the in the
case of the HD 25-1. Nevertheless, the vintage/studio Sony look paired with a enough
isolation to suppress basic background noises in buses and streetcars makes it a good and
honest companion for daily commuting or walking around on campus. Since the V6 was
originally designed for studio applications, the build quality leaves little to be desired.
Sound-wise, this is a bass-heavy headphone. Although nowhere as strong, it reminds of
certain boom-box qualities, i.e. strong yet not overly refined. Further, there is a certain
harshness in the highs which may cause fatigue over extended periods of listening time. As
for sound balance, the Sony leaves the impression as if the ‘loudness’ button or ‘rock’ preset
was applied.
8
See 3.4 for the benefits of coiled/straight cables
11
All in all, the V6 is an inexpensive, portable headphone with decent looks, decent isolation
and decent sound quality. In this price range, there are better options (AKG K 81), but the
Sony V6 remains a solid choice.
12
Sennheiser HD 25-1
Price: $200
Used: around $140
Type: Supraaural
Cable: 1.5m, straight
During the past two years, the Sennheiser HD 25-1 has been more or less my main portable
headphone, which is why I can certainly be accused of having a bias towards this headphone.
However, I like to think that this bias is not without good reason.
From a portable point of view, this headphone has everything you need: No sound leakage,
excellent isolation (only second to Sennheiser HD 280 Pro), lightweight, small although not
foldable, angled headphone plug (Ipod users will appreciate this fact), short headphone cable,
highly efficient, nearly indestructible, all parts are replaceable and it’s not too ugly either. On
the downside you have somewhat compromised comfort due to the supraaural design and
certain drawbacks in the sound quality department. Nevertheless, other than canalphones, this
is as portable as you can get without sacrificing too much sound quality. Its biggest asset is
that it is one of the few decent closed headphone which I can comfortable hang around my
neck, which is possible due to its supraaural nature and small ear cups. It is, however,
suggested to buy a pair of velour pads in exchange for the sweat-inducing and less
comfortable pleather pads. Especially long-term comfort is increased by the velour pads.
In my opinion, the HD 25-1’s most striking quality is that you can easily hang it around your
neck. I have yet to find that in any other decent sounding closed headphone.
13
Sound-wise, the HD 25-1 is a bassy headphone with a clean midrange and decent highs.
Moreover, detailing is good and it has a groovy character. On the downside, sibilance can be a
problem, especially on brighter sources. Further, the HD 25 has a very small and rather
compressed soundstage that might turn a lot of people off. Sometimes it sounds a bit strained
and it doesn’t have any particularly euphonic qualities either. In fact, some people describe
the HD 25-1 as dark or dull, which I believe doesn’t hit it either as it also depends on where
you’re coming from.
From a sound quality perspective, it’s probably not worth its price but if I was after sound, I
wouldn’t buy closed headphones to begin with and the HD 25-1 combines all the advantages
of closed headphones. For me, the HD 25-1 has proved to be the only worthwhile alternative
to canalphones. It can be very useful for urban commuting and other portable applications
where constant fumbling with headphones is required. Sound-wise I would put it on the same
level as the Ultrasone HFI 650, which, however, is not quite as portable (3m cable, slightly
worse around-the-neck-ability).
To add one note, I have to admit that the looks are not that great and the cups are thicker than
on the Sony V6. But what are the better-looking alternatives? The Sony MDR V300 certainly
looks good (at least I think so) and you can hang the headphones around your neck but it sure
doesn’t sound good. The smaller-sized Sennheiser PX200 offers much less isolation and
doesn’t sound as good the HD 25-1 either although the PX200 gives the user more overall
flexibility (foldable and fits easily into a pocket). The Sony V6 is not overly neck-friendly on
top of that. And to be honest, the HD 25-1’s looks are not that bad.
Frankly, as far as portable, full-sized headphones are concerned, I believe that the Sennheiser
HD 25-1, despite the recent additions of worthwhile competitors such as the AKG K81, is still
the one to beat.
(Reference diagram)
14
Ultrasone HFI 650 Trackmaster
Price: $180
Used: around $150
Type: Circumaural
Cable Length and Type: 3m, coiled
The Ultrasone HFI 650 Trackmaster is a foldable headphone that combines portability with an
exciting sound.
Due to its compact ear cups, decent isolation and ability to be folded, the Ultrasone depicts an
interesting alternative to the Sennheiser HD 25-1 and Beyerdynamic DT 250-250. When one
takes into account that it does not necessarily need an amp to sound good, then the
competition leaves only the HD 25-1. And the Sennheiser should fear the competition because
the Ultrasone offers a circumaural design which may be more attractive to people that don’t
like the HD 25’s supraaural design for long-term wearing. However, I don’t find the comfort
to be particularly superior especially because the sweating factor is comparably higher once
you use velour pads on the HD 25-1. The Ultrasone headphone provides decent isolation. The
ear cups can be turned outside, which can be useful for DJ-ing.
On the sound quality side, the Ultrasone can score with a strong and deep bass and a very
exciting yet also bright sound. The headphone is detailed and offers a fairly three-dimensional
soundstage. However, the headphone’s frequency response is not very balanced due to a
lacking lower midrange and boosted treble. With certain instruments and vocals, it lacks body
resulting in a thin and harsh sound. Sibilance is another issue that can cause listening fatigue.
15
Nonetheless, if you can get used to its idiosyncratic voicing, you will be rewarded with a
thrilling, portable headphone that is also excellent for gaming (good 3D positioning). It
sounds better than the Sony V6 and some may prefer it over the Sennheiser HD 25-1, too. I
personally couldn’t handle its treble and don’t need the gaming capabilities which is why I
much prefer the darker sounding and more practicable HD 25-1 for portable applications.
16
Beyerdynamic DT 250-250
Retail price: $180
Used prices: Around $140
Type: Circumaural
Cable Length and Type: 3m, coiled
The Beyerdynamic DT 250-250 is a very capable headphone and best described as a great
allrounder without any fatal flaws.
Due to its fairly compact size and low profile, its portability is only second to the Sennheiser
HD 25-1, Ultrasone and Sony V6. However, compared to the HD 25-1 it feels somewhat
cumbersome to put the DT 250-250 around the neck. It should be noted that the HD 25-1 is
the only full-size headphone which I feel comfortable laying around my neck. The coiled
cable is bothersome but not necessarily a bad thing for portable applications. The ear pads are
a bit small and may pose a problem to big-eared users. Nonetheless, comfort is good due to
the use of velour pads and wearer of glasses should find the combination of medium clamping
force and velour pads to be a winning combination for portable usage.
On the portable downsides, the isolation is comparably weak and an amp is almost mandatory
unless the DT 250-250 is driven from an adequately strong portable player. I am somewhat
undecided as to whether an amp is really necessary since this also depends on your average
volume levels.
In terms of sound quality, the Beyerdynamic is no slouch either and in fact, competes for top
honors alongside the A900, AKG K271, Beyerdynamic DT 770-80 and DT 831. While the
17
DT 250-250 does not offer the highest order of excitement, it has a coherent, detailed, and
well balanced sound, which causes no to very little listening fatigue. Its only sonic flaw is that
the notes sound a bit too soft at times leading to a more diffuse presentation. On the other
hand, the DT 250-250 is quite forgiving when faced with badly recorded/encoded mp3s. A
relaxing headphone that will especially please in the long-term.
Some users have complained about channel imbalances with their pair of DT 250-250 as
Beyerdynamic’s quality management on this particular headphone apparently is not always
flawless. Keep this in mind when buying used.
If you can live with its practical limitations, I rate this headphone quite highly and consider it
a good choice for semi-portable use with an amp for on the road and at home.
18
Beyerdynamic DT 250-80
Price: $180
Used Price: Around $120
Type: Circumaural
Cable Length and Type: 3m, coiled
The Beyerdynamic DT 250-80 looks like the DT 250-250, smells like the DT 250-250, but
just doesn’t sound quite like it.
Compared to the DT 250-250, this one is slightly more distant sounding and with an certain
dullness on top of that. Highs are not as extended and the bass is more muddy. There is a
particular mid-bass hump which may at times give the impression of a punchier bass. The DT
250-80 is also slightly less detailed.
Although this headphone has a lower impedance of only 80 Ohm, it is not much power
friendlier than the 250 Ohm version and may still require an amp if the source is particularly
weak or if the required volume levels are rather high. If it weren’t for its bigger brother, the
DT 250-80 would be an interesting alternative to the Ultrasone and HD 25-1 for the portable /
semi-portable market. Sound quality-wise it shares many of the DT 250-250’s virtues such as
a well-balanced frequency response and the ability to bring out the inner beauty in many
songs. If you can find a good deal on the used market, go for it. Otherwise, please opt for the
DT 250-250.
19
20
Sennheiser HD 280 Pro
Price: $100
Used price: around $80
Type: Circumaural:
Cable: 3m, coiled
In my humble opinion, the Sennheiser HD 280 Pro is one of the least fashionable headphones
ever made and I did not really dare testing out its portable merits. It is, however, the most
isolating full-sized headphone in this review.
The comfort is mediocre due to the strong clamping force and coupled with the pleather pads
it can cause some sweating, too. Isolation is great as already mentioned and its sensitivity is
high enough to be driven from portable players. Build quality seems to be very good although
there have been complaints about cracked headbands. Nevertheless, Sennheiser is usually fast
with repairs and offers a 2-year warranty.
Sound-wise, the HD 280 does not shine nor does it fail anywhere. It is fairly balanced with a
punchy and low-reaching but not overly pronounced bass. The midrange is reminiscent of the
HD 25-1 being a bit boring or quite flat depending on how you see it. The treble is a bit
recessed and certain instruments or vocals are not presented with as much forte as they
probably should or do not possess the air they could. The soundstage is good and detailing is
about the level of the HD 25-1. Overall, this is a solid performer without serious flaws like
some of the other contenders comprise.
Summing up, the HD 280 can be a good solution for a cost effective music, movie watching
or gaming headphone where isolation is required or sound leakage to be avoided. It sounds
better than the Sony V6 or Sennheiser PX200 and more open than the HD 25-1. However, its
huge size imposes severe limitations on its outdoor employment fields and the less than ideal
21
comfort hinders it to be a serious alternative to the more expensive stationary headphones like
the K271, A900 or DT 770-80. If you can get past its look, I guess you could use it as a
portable headphone as well.
Beyerdynamic DT 660
Price: $200 (I bought it for €100 from a German online retailer)
Used Priced: Not many used models around yet
Type: Circumaural
Cord: Straight, 3m
The new generation from Beyerdynamic includes the open Beyerdynamic DT 440 and DT
860 as well as the closed DT 660. Compared to the older generation DT 250-250 this
22
headphone’s sound goes into a different direction, which may not be welcomed by everyone
but embraced by others.
From a portable perspective, the DT 660 fills the niche between the DT 250-250 and the more
stationary AKG K271, A900 and DT 770-80. However, due to its high sensitivity, it can be
easily driven from most portable players - something which the DT 250-250 cannot.
Beyerdynamic has used a foldable headband although the folded state is still somewhat bulky
and it makes the headphone bigger than it could have been without the foldable headband.
Isolation is also better than the DT 250-250. Comfort-wise, the ear cups are bigger and also
suited for XXL-ears. One drawback of the hugs ear cups is that putting the DT 660 around the
neck is almost impossible. The package includes ear pads made from both pleather and some
kind of cloth. In combination with the latter ear pad material, the DT 660 can be worn for
extended periods of time without noticeable discomfort.
Sound-wise, the DT 660 is bright, detailed, fast, sharp and exciting. Unlike the Ultrasone with
its distinctly boosted treble, the Beyerdynamic simply raises its overall treble level. Listening
fatigue and harshness level are low notwithstanding. Combined with a punchy bass, a clean
midrange and the bright treble, this headphone will be the cause for some serious toe-tapping
activity. This is without doubt a lively headphone although I could have wished for a more
solid body to the sound. Sometimes, vocals sound airy but lack in the lower registers. All in
all, it offers an uplifting and light-footed performance that is second to only the best of open
headphones in this regard. Of course, those open headphones are also able to lay low and
provide other virtues where the DT 660 lacks such as resolution.
For this headphone I would also recommend the purchase of an 120 Ohm adapter 9 to tame the
brightness and increase the overall balance a bit. This, however, will reduce its efficiency
whereby an amp will be necessary.
Summing up, this is a unique headphone and with the right user, this will be a deadly
combination. Its semi-portability (big size but high sensitivity, foldable and acceptable
isolation) paired with a highly exciting sound makes this a good choice for both portable and
stationary use. I found it to be a nice headphone for gaming, too, and an worthy replacement
for coffee. For a more balanced-sounding but just as semi-portable headphone, take a look at
the AKG K181.
9
Also see 3.4 Serial impedance adapters
23
AKG K 181 DJ
Retail price: $200
Type: Supraaural/Circumaural
Cable Length and Type: straight, 3m
The AKG K 181 DJ was released with the K 81 and based on my experience with the K 81,
my expectations were sky high. Could this possibly replace my Sennheiser HD 25-1?
Unfortunately, as good as the K181 turned out to be, it wasn’t meant to be the be-all-end-all
closed headphone.
First of all, it has some nice features: a mono/stereo switch and a switch for small/large club.
The “large club” option simply makes the bass unbearable however. These are very
convenient functions for a DJ. Size-wise, the K181 is much bigger than I thought it would be,
which makes portable usage rather difficult. It cannot be hung around the neck comfortably
and you’d probably need a healthy dose of self-confidence or complete neglect thereof to
wear this in public. One of the K181’s peculiar aspects is its mixture of supraaural and
circumaural earpads. They are big enough to be the latter but the hole to fit the ears in aren’t
big enough. I can’t say I’m a big fan of this hybrid design as it carries the advantages and
especially the disadvantages of both worlds. For one, even though isolation is good, it is too
big for portable usage and doesn’t offer the usually high comfort from circumaural
headphones. The soundstage also suffers from this. On the plus side, the earpads don’t extend
very far from the head and the sound is better compared to conventional supraaural
headphones. The cable is also too long for portable applications but quite nice when used
stationary. The K181 is also surprisingly efficient and while it does benefit from one, AKG’s
flagship closed headphone doesn’t need an amp to sound good. Its build quality is top notch.
Sound-wise, the K181 is truly excellent. The bass is tight and extended, the midrange clear
and detailed, and the treble both extended and natural sounding without any sign of harshness.
The tonal balance of the K181 is very good and close to what I’d call natural. Despite having
different sound signatures, I would put the K181 on par with the A900 as far as unamped
sound quality is concerned, and that says a lot. As already mentioned, the soundstage is not as
good as other fully circumaural headphones exhibit but still very good, especially with
regards to soundstage depth. Human voices have a sense of air and clarity as I have seldomly
heard from a closed headphone. As most AKG headphones, the AKG K181 doesn’t fall short
of transparency and resolution. And if you’re looking for impact, the K181 might not be the
first choice, but it does get your toes tapping when necessary. Compared to the AKG K K271,
the K 181 lacks in smoothness but overall, the K181 sounds like a much-improved K81 on all
levels. I liked it.
Summing up, I have somewhat mixed feelings about the K181. On the one hand, it is an
excellent sounding headphone with a lot of great features and aspects but due to a few killer
criteria, I just couldn’t find a permanent use for it. For stationary use, the comfort is too
lacking in my opinion and for portable usage, its big size is a major hindrance. If you don’t
have a problem with either of these two points, then the K181 might be just for you. If you
can live with its size, the K181 is the best-sounding portable headphone you can find and if
you don’t mind the comfort issues or work as a DJ, this is an excellent stationary headphone
with a portable flair. Just like the DT 660, depending on your needs, the K181 could be a
killer semi-portable headphone. Based on merits of sound quality alone, this is one of the best
in this review and I’m sure not few would find it to be the best.
24
Beyerdynamic DT 770-80 Pro
Retail price: $200
Used price: around $140
Type: Circumaural
Cable Length and Type: 3m, straight
Whenever people ask for the best headphones for bass, the SOP answer will be:
Beyerdynamic DT 770. There are several version of this headphone but the best sounding one
is the DT 770-80 Pro10.
The comfort of this headphone is excellent - unless you have an oversized head in which case
the headband will not extend far enough. Portability is rather low due to the big ear cups and
hence better suited for home or office use. The DT 770-80 is nearly indestructible, too.
However, due to power requirements, an amp is necessary, especially in order to bring out the
bass. The isolation is good enough to block out most of the noise of computer fans or buses.
Sound-wise, this headphone offers a lot of bass although the rumors about it being a bass
monster might be somewhat exaggerated. Compared to speakers of car stereos, this is still
child’s play. Nevertheless, there’s no other headphone in this price range that offers more bass
quantity11. The bass definition and tightness needs improvement however. The rest of the
sound is fairly balanced with a upfront presentation of vocals and instruments. The treble is
well extended up to a certain point as the very upper frequencies may lack some air. The
soundstage is very good and surpasses that of most of the headphones in this review except
for the A900.
10
I found the DT 770-80 to be noticeably superior to the DT 770-250 mostly due a more even-handed frequency
response.
11
The Grado PS-1 is probably the only headphone with more bass
25
The DT 770-80 offers many qualities that a lot of people will be happy about and most of its
shortcomings shouldn’t bother the majority of listeners. This is an excellent headphone for
both gaming and movie watching. Of course, you can listen to music with it as well. It may
not be as portable as the Ultrasone, HD 25-1 or DT 250-250 but its isolation can be of use in
office environments or during long train travels or if you don’t want to bother or be bothered
by your roommates or family.
26
Beyerdynamic DT 83112
Retail price: $180
Used price: around $100
Type: Circumaural
Cable Length and Type: 3m, coiled
I think the best term to describe this headphone would be „underrated“. This can be easily
verified if you look at the prices these headphones go for on the used market, i.e. just around
$100. Beyerdynamic is mostly famous for its DT 770 bass monster and their flagship model,
the DT 880 which rivals competitor such as the Sennheiser HD 650 or Grado RS-1 for the top
spot in the sub-$1000 headphone market. However, it is exactly the DT 880 and DT 770-80
which the DT 831 shares the most similarities with. In fact, it sounds pretty much like a DT
880 / DT 770-80 hybrid with some added treble on top. Most people will be put off by its
bright presentation, especially when directly compared to other headphones in a quick A/B
comparison but they will miss out on the DT 831 exquisite qualities of which there are plenty.
Comfort-wise, the DT 831 is alright for a home headphone although the clamping force can
be a bit strong on the jaws. The isolation is comparable to the DT 770-80, i.e. pretty good and
the sensitivity is on the borderline between efficient and inefficient. My Ipod on some
occasions had a hard time but sounded just fine on others.
The sound of the DT 831 is certainly bright but the treble is not necessarily fatiguing. One of
the DT 831’s strengths is a very impactful and full-sounding bass, almost rivalling the DT
770-80 in this regard. Other audiophile requirements such as resolution, transient response or
soundstage were met with excellence by the DT 831. This headphone sounds very good with
12
Added on March 10th
27
vocals, especially female ones and did a good job for gaming and movies, too. I highly
recommend using a 75 or 120 Ohm adapter with the DT 831. While it reduces efficiency, the
brightness is tamed a bit and the overall frequency balance grew more to my liking.
If you don’t mind brightness, the DT 831 gets my recommendation. While the following
statement can be said of pretty much any headphone out there, it seems to be particularly true
in the case of the DT 831: The technical capabilities are there, you just have to like its tone.
Audio Technica A900
Price: $200
Used: around $160
Type: Circumaural
Cable: 3m, straight
The A900 is without doubt a thoroughbred home headphone. Despite its considerable weight,
comfort is very high and you literally sink into the big, cushy ear pads, which might get a bit
warm during hot summer days. The headband utilizes a so-called 3D-Wing system, which I
found less impractical than the conventional continuous headband but it handles the job.
Speaking of build quality, it does not look as robust as some of the other headphones and if it
weren’t for its size already, I would be wary about portable usage with the A900. The
isolation level provides enough reclusion from moderate background noise.
The A900’s most important asset, however, is its ability to sound good out of any source and
with pretty much every kind of music. On the downside, the A900 doesn’t sound much better
from a $400 home system than from a mere Ipod although certain improvements are there. It
is forgiving towards lower end sources and recording material.
28
This headphone was also very good with gaming and movie watching, a jack of all trades so
to speak. The DT 770-80 and HFI 650 are better for gaming but they have their own
drawbacks: The DT 770-80 needs an amp and, in my opinion, may not sound as balanced as
the A900. The Ultrasone is much less comfortable and does not please as much with music.
For movie watching the DT 770-80 did better, too, but the same reservations apply. For mere
music listening only the AKG K271 was considerably better but not without spending
considerable money for a better amp and source.
Summing up, I believe this headphone does everything you need from a home headphone.
And for what it does it even outperforms open headphones. For “just” $200 you get the whole
package of music listening, gaming and movie watching without worrying about amps or high
end sources. Once you decide to upgrade to a better system, the A900’s limitations are
revealed but until then, the A900 is excellent value.
29
AKG K271 Studio
Price: $200
Used: around $150
Type: Circumaural
Cable: 3m, straight
The AKG K271 has won many awards in the recordings/mixing industry and is by many
considered as the best-sounding closed headphone for $200 and under although it needs to be
noted that the same claim is being made for the A900, too.
Initially, I didn’t want to give this headphone a high grade on isolation because I thought that
a high comfort and low clamping force implied low isolation. After some tests, however, I
was proved wrong because both isolation and comfort are very good. The headphone is
lightweight but due to the use of pleather, the AKG is not completely sweat-free. The
isolation may vary with different ear sizes because the distance between ear and drivers is
short and depending on your ear/head shape, there might not be enough of an isolating seal
between headphone and head (big ear cups but rather shallow).
Due to its big size and inability to be folded, the AKG is extremely un-portable and because
of the huge ear cups almost impossible to be hung around the neck. Build quality is very good
and considering its studio heritage, it better be. The cable is exchangeable, too.13
Sound-wise, the AKG’s bass albeit detailed and refined is very light, which many including
myself dislike about this headphone. The good midrange is what it’s famous for and the highs
13
Also see 3.4 for cable upgrades
30
are very good, too. Due to the sweet yet highly resolving treble, listening fatigue is very low
and there’s no harshness or sibilance to speak of. The K271 is a very detailed headphone with
a decent soundstage and good imaging. Some consider the AKG K271 to be colored and I
have to say that the slight hill in the midrange does not sound to me as very accurate.
However, the imbalance is very well-integrated into the rest of the tonal spectrum, which
makes for a very natural feeling overall.
I think the AKG K271 is a very good headphone for stationary use where isolation is required.
Yet compared to the A900, this headphone requires some fine-tuning to get the sound right
and an amp is the almost mandatory first step. The A900 is more versatile since it’s better
suited for gaming and movie watching and it neither requires nor benefits greatly from an
amp, which makes it a better option for a simpler setup. Further, even compared on a high end
rig, some may prefer the A900 for its tone, stronger bass and better soundstage width. But in
the end, as far as resolution, midrange, treble, attack and other technical issues are concerned,
the AKG K271 will most likely outrun the A900 with a more sophisticated backend. If you
have the proper equipment to back it up, I think the AKG K271 is the best sounding
headphone in this review -- all sonic limitations, especially in the bass, in mind.
Etymotic ER-4P / Etymotic ER-4S
Price: $230
Used: around $160
Type: Canalphone
Cable: 1.5m, straight
The Etymotic ER-4S is basically an ER-4P with an added serial resistance of around 75 Ohm.
The ER-4P is easier to drive from portable players14 but the ER-4S sounds better. It is
therefore recommended to buy the ER-4P plus an ‘P to S’ adapter cable. While there may be
differences between these two canalphones, they were small enough for me to focus only on
the S version especially since my more powerful players was able to drive them.
When I heard this canalphone at home for the first time, it made a very good impression on
me because it was detailed and fairly balanced. The bass was tight, refined, not overly strong
but definitely there. Perhaps a tad on the bright side overall but not something I couldn’t
14
On certain portable players such as the Ipod, which has limited output capacitors, there will be a bass roll-off
with low impedance headphones such as the ER-4P.
31
handle. So along came the first serious portable listening test. I listened to the Etymotics all
day and came to the conclusion that there just wasn’t enough meat to the sound. Too little
bass, too thin and too much treble (often sibilant) for portable applications. The following
days did not show any significant improvements until I used a player with heavy boost. The
bass boost certainly improved things because due to the bass boost’s low quality, parts of the
midrange were elevated as well, which contributed towards a more balanced sound. The Etys
are analytical and revealing canalphones, not warm in the least. I found them to be great for
classical music but not so much for pop and rock. It is not a groovy headphone but more of a
musical scalpel.
The ER-4S is a very precise headphone with the notes being outlined very sharply but
sometimes it was just too much for portable background listening. Further, part of the
“detailing” probably derived from a boosted upper end. By down-EQ-ing parts of the treble,
some of that “resolution” was lost mysteriously. Nevertheless, it still remained among the
most detailed headphones in this review.
As with the Shure E3, the sound was also too much in my head and the HD 25-1 just gave me
a “bigger” sound.15
One cure to the Ety’s brightness was by using the soft flex sleeves from the E3 which gave
the ER-4S a more balanced sound with less piercing highs. The Ety’s foam tips also worked
but I always found them to be somewhat uncomfortable. I highly recommend purchasing a
pair of Shure soft flex sleeves for use with the ER-4P/S. With the soft-flex sleeves I have been
using the ER-4S much more often than I used to.
(Second line for the ER-4P)
Shure E3
Price: $130
Used: Around $100
Type: Canalphone
Cable: 1.5m, straight
15
More on this in chapter 3.1
32
In direct comparison at home, the Etymotic offering simply bashes the Shure from an
audiophile point of view - absolutely no contest at all. However, when being used portably,
it’s a different story.
One thing about the E3 is that their treble is severely recessed and even an equalizer does not
bring it back. Further, the E3 has an upper midrange hump which forcefully pushes female
vocals and brass instruments to the front. To finish things off, the bass is stronger but less
detailed and muddy compared to the Etymotic.
So much for theory. In practice, the midrange hump was useful in noisy environments where
the midrange cut more easily through the background noise and the muddier yet also stronger
bass was highly welcome. In the case of canalphones, I’m thankful for any extra dB in the
bass. Moreover, there’s a certain tonal richness to the E3 which the rather cold and analytical
Etys did not have. And to finish portable things off, the E3 has a less microphonic cable than
the Etys. For long-term listening the Shure were less fatiguing, too.
So much for practical theory. What about adding some bass boost or using the Shure sleeves
on the ER-4S? In fact, when I use all the given means I have, i.e. bass boost and other sleeves,
then the ER-4S does become my canalphone of choice. It’s a middle way between the Shure’s
midrange and bass emphasized and the Ety’s treble emphasized approach. I also blame most
of the Ety’s flaws on the triple flange tips because used in conjunction with the Shure, even
the E3 starts to sound sibilant and bright in an unrefined fashion for my tastes.
Pesonall conclusion on Shure vs. Etymotic
My recommendation is that if you have something with a bass boost and can use either the
foam tips or the Shure tips on the Etymotic canalphones, go for the Etymotic as it has the
more pronounced technical capabilities such as headstage and resolution. With my given
means (bass boost, Shure flex sleeves) I find the Etys to be close to ideal at the moment. In
any case, you also need to consider the significant price difference and it might well be that
the new Shure E4 manages to surpass the Etymotic ER-4S.
Update: In the meanwhile I have been able to own the Shure E4, which provides a great
middle way between the E3 and E4. It is a very balanced headphone without the E3’s severe
treble roll-off. Considering the small price difference, I would definitely recommend the E4
over the E3. The E3’s only remaining merit is that it’s a bit more groovy.
33
2.3 In-Detail Review
Due to a variety of excellent reviews whose level I wouldn’t be able to match given my
limited dedication and expertise in regards to canalphones, I did not review the Shure E3 and
Etymotic ER-4P/S in full detail.16
As I have already written a full review on the Sennheiser HD 25-1, I will not do so in the
context of this review. You can find my full review of the HD 25-1 following the link
provided.
I did not review the Beyerdynamic DT 250-80 in full detail because I did not feel the
necessity to review a headphone that shares the same size, looks, price as the DT 250-250,
and with the only difference being an overall worse sound. The additional impedance does not
make the DT 250-250 a lot harder to drive either.17
The HD 280 were not included because I lost my In-Detail listening notes. I also lost some of
my notes on the A900. Therefore the report will not be as “In-Detail” as it should have been.
Nevertheless, as with most of the headphones reviewed you can find many cross references
throughout the entire review section.
The Audio Technica ATH-FC7 was not included because I didn’t deem it worthy to be.
The AKG K 81 and HD 201 were added at a later time and offer a more streamlined style.
The review methodology, however, has stayed the same.
The AKG K 181 was unfortunately not included because I had already sold it before
proceeding to the In-Detail review part.
Sennheiser HD 20118
If you could judge a book by its cover, the HD 201 would pass as „ambitious” as Sennheiser
somehow tried to achieve a modern look by using a slim-line design and while I’m not
necessarily a fan of retro-looks, I’m not particularly thrilled by Sennheiser’s use of the large
silver area either. I think they should have stuck with a more utilitarian colour scheme that
looks business as in the Sennheiser HD 25-1. Nevertheless, the slim design is very well-suited
for portable use and not many headphones stick out less to the sides than the HD 201 does.
The overall build quality feels a bit cheap although this is very much expected at $20. On the
more serious issues I have with the HD 201 is the flimsy, pretty microphonic and long cable
that gets kinked very easily. A shorter cable is much better for portable use. I also prefer the
HD 25-1 cable’s single-sided-ness and the HD 201’s straight headphone plug is more prone to
being pulled out while listening than an angled plug.
One nice aspect is that the HD 201 can be worn around the neck fairly comfortably something which only the HD 25-1 managed in a even more accomplished fashion from the
headphones featured here. Personally, I consider this a very important consideration for
portable usage.
Two very good comparisons: Comparative Review 1, Comparative Review 2.
chapter 3.3 - ‘Volume Testing with Ipod’
18
Added on March 10th
16
17
34
Comfort-wise, there’s not very much to complain about. Despite the ear pads being a tad too
small, shallow and less than ideally cushioned causing the earlobes to be compromised in
comfort, the headphone’s little weight and ergonomically fitting design provide relatively
decent comfort for a closed headphone with a portability factor as high as the HD 201 has.
The isolation could have been better.
One major issue with the HD 201 is that it is rather inefficient. Although my Ipod provided
sufficient juice most the time, there were many occasions where I wished for more flexibility
in volume.19 I tried the HD 201 out of a cheap USB stick-type MP3 player and the sound was
far from enjoyable. Combined with the little isolation and the not so strong bass, the HD 201
was not well-suited when ambient noise was predominant like in subways or noisy areas in
general.
The Sound
Finally touching on the subject of sound quality we also return to the HD 201’s strengths.
Frankly, the HD 201 sounds remarkably good and transparent for a $25 headphone and there
are probably not many that sound better at twice its price.
The bass is the tightest you can get for this budget although it lacked the overall “oomph” of a
Sony V6 or HD 25-1. Bass depth was not outstanding either but completely devoid of the
usual muddy bass you normally find in closed headphones this cheap. If you expect boomboxstyle bass, look elsewhere although, as already mentioned, I found the overall amount of bass
to be insufficient. Perhaps I should add some words regarding the “weak” bass. I find that
most portable headphones tend to have more bass than home headphones, be it to compensate
for the background noise or because bass on the go is just a heck lot of fun. If the Sony V6,
Sennheiser HD 25-1, Ultrasone HFI 650 or even Koss KSC-35 share a common trait, it would
be their bass bias and it’s something I really appreciate when being on the road. “Compared to
home headphones, however, the HD 201 does not necessarily have a weak bass and only to
meet my portable requirements it simply was not quite enough” is what I would like to say but
unfortunately, the HD 201 has the weakest bass from all the headphones tested, i.e. including
the stationary ones. Bass-mongers need not to apply here.
The HD 201’s midrange is more forward compared to the Sennheiser HD 25-1 or the HD 650.
Despite their darker tone, I’ve always liked Sennheiser headphones for their overall frequency
balance and the HD 201 is no exception. In this regard, it outperforms the HD 25-1 with its
sharp treble peak in the mid treble that gives rise to its sibilant nature. The HD 201’s treble
lacks the finesse, air and texture compared to more expensive headphones and can be
characterized as somewhat tinny and unrefined. However, treble extension is surprisingly
good and the HD 201’s sound is very easy on the ears. One major issue is that the HD 201
exhibits strong sizzling with ‘s’ consonants, i.e. sibilance. However, this does not cause
serious listening fatigue like the Ultrasone HFI 650 does or the HD 25-1 to a weaker extent.
The HD 201’s soundstage is bigger than the HD 25-1’s or even the Sony V6’s. The
holograhpic imaging is quite astounding for a headphone in this price class. Resolution was
the weakest from the headphones tested but not significantly so.
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My E-MU 1212m soundcard had problems driving the HD 201 from its line out using the +4dB pro audio
level and I usually had to apply an extra gain of 2-5dB for satisfying sound volumes. In that regard, it was even
harder to drive than the HD 650. I am not completely sure why this was this case as it is probably not only a
matter of sensitivity and power and perhaps an impedance issue as well. In any case, you might encounter
similar problems when trying to drive the HD 201 directly from a soundcard’s line out.
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Most instruments and human voices sounded “right” on the HD 201 and I couldn’t hear any
serious colorations, neither bad nor embellishing ones. As far as transient response was
concerned, the sound sounded pretty fast but lacked what could be described as meatiness or
palpability that even the inexpensive Koss KSC-35 manages to convey. It does not achieve
the visceral impact of the HD 25-1, HFI 650 or V6 mainly due to the HD 201’s weaker bass.
While I don’t mind a politer sound while sitting in front of the computer, a more punchy
nature would have provided me with more fun in portable situations. As a result, the HD 201
is not as toe-tapping or engaging as its pricier competitors. This of course, was more of an
issue with pop, electronica and rock than with jazz or classical.
One other issue I had with the HD 201 is that it could sometimes sound a bit hollow although
I was not completely sure whether this was frequency dependant or more of an inherent
soundstage characteristic or an combination of several factors including the transient
response.
Summing Up
All in all, the HD 201 does little wrong and many things right at its price. Due to its more
forward and brighter nature compared to its siblings HD 25-1 and HD 650, the HD 201 should
be able to find its followers even among the ranks of AKG, Sony and Grado aficionados. If it
were easier to drive, used better cushioning, a shorter and more solid cable, had a more meaty
sound, a stronger bass, better isolation and didn’t use the black and silver colour scheme, the
HD 201 would have been perfect. But since when could you get perfection for $20? As it is
now, the HD 201 is still very good for the price asked although with some reservations if you
plan to use it for applications like commuting where loud ambient noise is unavoidable or if
you like your bass strong. Unfortunately, the only average long-term comfort doesn’t turn the
HD 201 into an ideal office or library candidate either.
While I prefer the slightly more expensive Sennheiser PX200 as a low-price closed
headphone due to its smaller size, shorter cable, greater comfort and better looks, the HD 201
does offer more sound per buck if that is the main concern. For $60 you can also get a Sony
V6 which has a significantly greater bass output (perhaps overly so), enhanced looks and
better isolation. The HD 201 on the other hand offers a more balanced sound than the V6,
which has a bowl-like frequency response and some nastiness in the highs. Nevertheless,
assuming you can deal with its treble, which I could, the V6 is more engaging and fun to
listen to, especially in portable situations.
Personally, I don’t quite understand Sennheiser’s engineering goals behind the HD 201. It is
not efficient enough, has too long of a cable and does not have the necessary bass output,
punchy sound or isolation to be a really great portable headphone for the standard consumer
demand. And looking at the HD 201’s price, you don’t expect the average Joe to buy an
headphone amp. However, judging by its design and long-term comfort, it is not an ideal
stationary headphone by all means either. Perhaps Sennheiser simply tried to make a jack of
all trades and for just $20 I think they did exceptionally well.
Sony V6
Bass
The Sony V6 has a lot of bass, mostly in the upper bass region. Overall the bass sounds a bit
muddy and it’s neither as tight nor as fast compared to the other headphones. But what did
you expect at this price point? In fact, I find the abundance of bass to be a nice asset for
portable activity, especially in conjunctio with players that don’t excel in bass. Due to the
upper bass and lower midrange hump acoustic basses don’t have as much precision as they
36
should have. The bass isn’t the most detailed either and summing up, ‘fungous’ is probably
the appropriate description for it.
Midrange
The midrange is tilted clockwise towards the lower parts of the midrange leading to a fairly
warm impression. It certainly doesn’t have the alluring qualities of a AKG K271 nor the
brilliance of most of the Beyerdynamic headphones. Right down the middle the headphone
lacks body as if there was an U-shaped valley in the frequency response. Quite the opposite to
the AKG K271’s midrange, which is bent upwards rather than downwards as on the V6.
Highs
There’s a certain harshness in this headphone which became quite bothersome after extended
listening periods. It’s not a brightness in a sense that the upper midrange and lower treble are
generally raised to a higher level but more of a peak somewhere. Treble extension is not the
best of the bunch but it’s not as disappointing as the price difference might suggest.
Nonetheless, due to less than stellar detailing, the tone of cymbals and other instruments with
high frequency parts don’t sound very natural.
Balance / Transitions / Even-handed frequency response
The Sony V6 sounds as if the loudness button was applied or the ‘rock’ preset activated. Lots
of bass and lots of highs with the midrange being left out at times. Tonally it’s close to the
A900 but not nearly as refined.
Resolution
Worse than the K81 but nonetheless very good for this price point.
Headstage / Soundstage
Not much to say other than it is slightly bigger than the HD 25-1’s soundstage.
Visceral Impact/Attack
The attack of the V6 is a bit slow but there’s quite some punch down there due to the strong
bass, so you could call it a punchy headphone.
Human voices / Instruments
Nice rendition of vocals, at least not too thin. Nothing spectacular but that’s what I expect
from a $60 headphone. Distorted guitars were too aggressive for my tastes.
Practical Considerations and Summing Up
Comfort is very similar to the Beyerdynamic DT 250-250 but the Sony uses pleather instead
of velour. The pleather is more sweat inducing and therefore less comfortable. However, you
can buy the Beyerdynamic DT 250-80/250 velour pads and install them on the Sony V6.
Cable microphonics is insignificant.
The V6 is the consumer model of the Sony 7506. Some people claim that there are sonic
differences, others say there are no differences at all except for a different marketing.
An amp slightly tightens the bass but does not improve the sound quality very much overall.
I expected much less from a closed $70 headphone but except for the harshness in the highs
and somewhat overblown bass, this a very solid, portable headphone at a reasonable price
point. It looks good, can be worn around the neck with only small discomfort, and offers a
solid package all in all.
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AKG K 81 DJ20
When writing a review, sometimes the issue arises of whom you’re trying to address and
whether you can get the message across. This, for instance, can be the case where you’re
trying to speak to both a highbrow audiophile as well as the casual listener. The casual listener
might crave for bass whereas the audiophile might be looking for definition thereof.
Fortunately for me, there’s little need to indulge in such diplomatic ambiguity when it comes
to the AKG K81. I have experienced that people from either side of the audio spectrum have
been extremely pleased by AKG’s latest outing and it has never been easier for me to give a
straight recommendation for a particular headphone with such few if’s and but’s.
But first things first. From the portable perspective, the K81 delivers quite strongly. It is fairly
small, can be folded, is very sturdy and has a pretty low profile despite the silver design
elements, which I don’t really fancy. The isolation is good and I’ve been quite pleased when
using the K81 on my daily commuting activities. Further, the K81 is easy to drive and doesn’t
need an amp to provide the punch and clarity of sound, which it already does without one.
Another major plus is that the K81 can be comfortably put around the neck – a very
convenient feature, which only supraaural headphones share.
However, being supraaural is a double-edged sword as comfort is reduced compared to
circumaural headphones, which might cause problems if you have pressure-sensitive ears.
Further, due to its supraaural nature and pleather pads, your ears may get rather sweaty during
summer. Also, the plastic headband doesn’t offer any cushioning, which might become
uncomfortable if your head shape differs from what the AKG engineers had envisioned.
Continuing with the drawbacks, the K81’s cable is two-sided, rather fragile looking and
simply too long. Addressing the latter issue, I have been using a Sumajin Smartwrap, which is
not an ideal solution – ideal would be a 1.5m cable - but it does the job.
Sound-wise there are few things to fault and more to be amazed about considering the price.
Let’s start off with its flaws. The K81’s bass, while being strong, deep and punchy, is
overbearing and bloated with certain types of music. When listening to a jazz piano trio, the
bass sometimes totally overpowers the piano and with certain pop or rock tunes, the melody is
being drowned in the bass. It is mostly the upper midrange and treble that is being suppressed
and I think it is mainly the midbass around 60Hz, which causes these issues, as both the lower
and upper bass are quite articulate and even by most standards. Another problem is that the
sound sometimes lacks lushness and air. Despite AKG’s reputed midrange clarity, I find there
to be a very slight dullness to the frequency response and lack of space to breath – both being
rather subjective and nit-picky observations.
Now, the good thing is that we no longer live in medieval times when equalizers on portable
players have been the exception. Even the Ipod has one. If you have a graphical EQ (sliders)
on your portable player, simply tune down the bass and slightly boost the frequencies in a
linear fashion starting at around 1 KHz. This is my personal tonal preference and everybody
should find its own. If you have a parametric EQ (adjustable frequency, gain and bandwidth
settings) and know how to use it, there’s no need for me tell you anything to begin with. And
if you have an Ipod, find a setting you can be comfortable with. I quite like the “jazz” setting
with the K81.
An EQ can alter major parts of a headphone’s tonal characteristics but technical capabilities
such as soundstage, resolution and transient response cannot be remedied with an EQ. This is
20
Added on September 20th. I used a more streamlined reviewing style this time around but the review
methodology has stayed the same.
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slightly simplified as tonal changes actually can lead to a different perception of soundstage
amongst many things, but we shall discard this degree of differentiation for the sake of
brevity.
This leaves us with the good stuff. To provide a run down of the K81 assets: The sound is
detailed and transparent lacking ever so slightly compared to the HD 25-1, which edges out
the K81 in terms of overall resolution. The K81’s soundstage is surprisingly good in terms of
width and depth with decent layering of sound considering its supraaural nature. There is also
AKG’s rightly famous midrange clarity, which sounds very neutral and right to me. The bass,
once toned down a bit, (still) provides all the impact and fullness you could ever dream of
from a portable headphone. Another important asset is that the K81 does exhibit any
harshness or brightness and only very little sibilance, which all keep listening fatigue to a
minimum. I also did not stumble upon any certain genre, which the K81 didn’t fare well with.
Its transient response is one of the best I’ve encountered in a portable headphone: palpable,
fast and with lots of PRaT. Human voices are rendered with both authority and a good dose of
realism.
Summing up, if you don’t entertain an apathy towards bass or have an EQ on your portable
player, if you were looking to spend not more than $100 on a pair of portable and closed
headphones and if you can live with the comfort-related implications of a supraaural design –
spare yourself the arduousness of reading through this entire review and just get the AKG
K81. I still consider the Sennheiser HD 25-1to be the superior product but at three times the
price of a K 81. My endorsement for a single headphone has rarely been stronger as in the
case of the AKG K81.
Ultrasone HFI 650 Trackmaster
Bass
The bass on this headphone is good: Strong, impactful and tight. The upper bass could use a
bit more presence but all in all it’s sufficient. It reaches low, a tad lower than the other ones
but still not as low as the DT 770-80. I would say the bass is one of the HFI 650’s strengths
even though it might need the right recording (with sufficient low and mid bass content) to
shine. The HD 25-1 for instance may offer the impression of more bass but that is mainly
because its upper bass and lower midrange are more prominent.
Midrange
The lower midrange is lacking but the upper midrange isn’t as hyped as on the Beyerdynamic
headphones. Due to the strong low and mid bass followed by a weak upper bass and lower
midrange, the headphone lacks body and sounds rather thin. This is further accentuated by a
strong lower treble.
Highs
This is the part I really dislike about the Ultrasone because it has a peak in the lower to mid
treble (around 5-6 KHz) which causes a lot of listening fatigue. However, if you look past this
issue, the highs are crisp, detailed and well-extended. This is without doubt a very exciting
headphone. Like the DT 660, the Ultrasone has a lot of initial impact on cymbal crashes.
Nonetheless, this headphone is also the most sibilant one of them all.
Resolution
Resolution is high and due to the treble emphasis, you get chunks of detail shoved down your
throat leading to a more detailed impression. Nevertheless, by taming down the highs using a
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parametric equalizer, the resolution was still there which leaves me to assume that the
Ultrasone’s inherent resolution is indeed very good.
Headstage / Soundstage
The ‘surround sound’ thing is just a lot of marketing to be honest. But still, the soundstage is
good; bigger compared to the DT 250-250 but smaller than DT 660 or DT 770-80.
Soundstage depth is not exceptional but not bad. Interestingly, the Ultrasone has a quite
holographic soundstage in nature and is very well-suited for gaming where positioning is
critical. I suppose they used some interesting field-equalization to create this three
dimensional soundstage. The treble also plays a role in the good soundstaging.
Visceral Impact/ Attack
Hard to deny, this is a very positive side of the Ultrasone: Exciting, fast and with bite.
Balance / Even-handed frequency response / Tone / Sound signature
The Ultrasone is probably the least balanced headphone out of the bunch: lots of bass punch
down there, very lacking lower midrange, some peak in the lower to mid treble. Listening to
the Ultrasone I can’t help thinking about colored neon lamps. Yes, it’s fast, detailed, exciting
and all but it’s just not a balanced or coherent sounding headphone. Certainly a sharpsounding headphone.
Human voices / Instruments
Vocals sound ok but as with the DT 660 or DT 770-80, they lack body. Sometimes, they
become too thin and sizzling. However, I have to admit that there’s a certain intimacy to the
“pixely” voices. Further, human voices are well-resolved and the tone isn’t too off.
The piano sounds right and better than on most of the other headphones. Guitars also crisp
and not overdone. Violins get a bit harsh at times. In the case of saxophones I need to make a
plea for more lower midrange and body again. Brass instruments in general sound too thin
and uneven for my tastes. But acoustic bass sounds really: no bloat, deep and strong.
Distorted guitars can sound too aggressive if you happen to catch the wrong frequency ranges
but it’s without doubt very exciting.
120 Ohm Adapter
I found that by adding a 120 Ohm adapter21 some of the imbalance issues were alleviated as
the treble level is reduced by a bit in relative to the lower midrange. There is a stronger lower
midrange and increased overall bass impression. Albeit more enjoyable, I still couldn’t chum
up with this headphone and the 120 Ohm adapter makes an amp necessary for portable use.
Practical Considerations and Summing Up
Compared to the HD 25-1 the Ultrasone is bigger but in exchange it is also foldable. Comfortwise, these are not bad but suffer from similar sweat issues as the Sony V6. Further, long term
comfort can be compromised if you have bigger ears. Cable microphonics are marginal.
Although an amp is not necessary, it provides an overall sound quality enhancement,
especially in the bass.
As you can tell, I’m not biggest fan of these headphones sound-wise and the addition of the
AKG K 81 into the mix has weakened the Ultrasone’s stance even more. In any event, it is
easier to drive than the Beyerdynamic DT 250-250, sounds better than the Sony V6 and has a
more forward and exciting sound than the comparably dull-sounding Sennheiser HD 25-1. Its
21
I bought one from Meier-Audio
40
strong bass and good soundstaging add to the pro arguments. It is excellent for gaming
(precise and three-dimensional staging, good for shooters) and you don’t really need an amp
compared to the DT 770-80 (the other gaming master). Unlike the DT 770-80, it is also more
portable.
Beyerdynamic DT 250-250
Bass
The DT 250-250 does not have a very strong bass. For some it may be too lean. However, it is
very clean, detailed and reaches low. It doesn’t have the fast bass attack of the DT660 or the
tightness of the AKG K271. All in all, the bass is a bit on the soft side but the overall bass feel
is not as anemic as the AKG K271. Probably not the DT 250-250 greatest asset but it fits well
in to the rest of the sound spectrum.
Midrange
The midrange is the most well balanced and natural sounding among all headphone tested. No
particular frequencies stand out. Both the lower and upper midrange provide seamless
transitions to the bass and treble. The upper midrange is a tad more prominent compared to
other headphones which lends the DT 250-250 its typical Beyerdynamic midrange: Slightly
more upfront and with a touch of coldness but more in terms of being crystal-clear than
sterile. In any case, the upper midrange bloom is not as prominent as on the other
Beyerdynamic models and most of all not at the expense of losing the balance as is slightly
the case with both the DT 770-80 and DT 660. It may not have the special midrange qualities
of the AKG K271 but it is not as colored either.
Highs
The highs are extremely well done and as good as the A900 or AKG K271 in this regard.
There are no signs of unwanted glare or harshness anywhere. Further, the treble extension is
excellent and very natural-sounding: Cymbal decays have just the right amount of initial
impact and decay. Female vocals taken on an airy character and the upper harmonics of most
instruments are rendered extremely well. However, at times the treble could use a bit more
bite, i.e. a stronger attack as it sounds a bit too soft overall. The A900 has more finesse in that
the bigger soundstage leaves more room for the treble details to literally spread in the auditory
space. Compared to the AKG K271 the DT 250-250’s upper registers are not as crisp but a tad
more sparkling if that makes sense.
Balance / Transitions / Even-handed frequency response
As already said, this is the DT 250-250 major strength: It is extremely well-balanced
throughout the entire frequency range without major humps or dips. Everything works
together just like an experienced and well-oiled yet slightly easy-going machine.
Resolution
The resolution is very good. The details don’t really stand out and grab you at the neck but
I’m not a big fan of this kind of Grado 325-esque detailing anyway. Everything is wellintegrated into the music.
Headstage / Soundstage
The headstage and soundstage is the one thing where the DT 250-250 is only mediocre or
even lacking. Nothing spectacular, especially with regards to the soundstage width. On
heavily-produced music it can become cramped at times. Nevertheless, instruments and
vocals are placed with precision inside the sound-field. The left-right separation is not as
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strong and feels quite natural. All in all, it is a very coherent soundstage, just not very big.
Soundstage depth with front to back is done ok, not great but decent enough.
Transparency
The notes sound somewhat diffuse but transparent notwithstanding. The A900, DT 660 and
AKG K271 are better in this regard however.
Visceral Impact/Attack
Not a lot of bass kick and the highs could use more bite. The midrange has enough body not
to sound ethereal but there’s just not the visceral feeling I can get from some other
headphones.
Transients
The fast changes in the music are not as sharp but quick regardless. It’s almost like a car
driver that doesn’t turn 90 in instant but takes a second to initiate the turn.
PRaT (Pace Rhythm and Timing)
This definitely not the Beyer’s strength. The DT 250-250 is not the most exciting or toetapping headphone although this doesn’t mean that it’s the school nerd either. It has a refined
yet reserved musical presentation. Just nowhere near the toe-tapping qualities of a DT 660.
Focus
I am not sure if this frequency related but the notes appear in a lightly blurry contour. It might
be due to a not overly emphasized treble which downright cuts into the music. The softer
transients sometimes make the sound picture a bit diffuse
Tone / Sound signature
To use an analogy: The DT 250-250 is like green tea. Contemplative, a well-rounded unit,
excels at nothing and fails nowhere either, which is its major strength. It can sound a bit
boring upon first listening but appreciation may grow in the long-term. Due to the DT 250250 naturalness you hardly get tired of the its comforting sound. All in all it sounds quite like
the HD 650 with just a bit more upper midrange and lower treble. On Diana Krall’s ‘Deed I
Do’ (Live in Paris) the DT 250-250 does not bring out the energy-laden fast paced Ms. Krall
but more so the romantically-facetted pianist in her. The hi-hats don’t force themselves into
the foreground but settle for a sparkling background sound. The same applies to certain violin
solos: Less virtuosity, more elegy. The DT 250-250 definitely gets you to appreciate the BNote. Whether that is a good thing is up to you.
Human voices / Instruments
Not as golden and song-like as on he AKG, not as seducing as on the A900, not as
emancipated as on the DT660 but just very good overall with its softer yet refined approach.
The inner beauty of human voices are brought out nicely. Most instruments sound very
realistic albeit slightly lackadaisical in nature.
Practical Considerations and Summing Up
The clamping force is stronger compared to some of the bigger headphones (AKG K271,
A900) but not as strong as the HD 25-1 or Ultrasone. The comfort is somewhere in-between,
too, mainly due to the nice velour pads. Little cable microphonics. Not foldable and will
hence take up some space in your bag. The build feels a bit flimsy but there are no sensible
joints to break and most parts are exchangeable.
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As already mentioned in the general review section, some users have complained about
channel imbalance issues on the DT 250-250 due to less than perfect quality control. Just keep
this in mind when buying used.
For both sound quality and volume reasons, an amp would be recommended although some of
my portable players are fine driving the DT 250-250 unamped.
Overall, I’ve tried hard to find a reason to keep this headphone as a portable addition because
I really like the sound, but in the end couldn’t justify the purchase due to its various
shortcomings in the portable sector: Insufficient isolation, not as comfortable when lain
around the neck and with the Ipod I’d need an amp. If offers excellent sound quality but is not
as suited as a home headphone as the A900 or K271. However, for semi-portable applications
where isolation is not as important, this is a fantastic headphone. My liking for the DT 250250 sound signature may partly stem from its resemblance to the Sennheiser HD 650.
Beyerdynamic DT 660
Are you a person who likes to turn up the treble on your computer speakers or kitchen radio?
If you answered yes, then you might really like the following headphone.
Let me start off by saying that I prefer the DT 660 with an added output impedance of
120Ohm (adapter) but for the validity of the evaluation I seldomly used the 120 Ohm adapter.
Bass
The DT 660 has a very nice, clean and detailed bass. It’s not as pronounced as on the DT 77080 or A900 but for this price class it is an excellent compromise between quantity and quality.
Tight with quite some punch. A bit slower once you add the 120 ohm adapter but more of it
(in this case ‘more’ is still a bit ‘better’ in my opinion) and I wish it could go a bit deeper. It
sounds really good with acoustic bass because it’s not as bloated as with some of other
headphones while retaining some of the natural bass bloom.
Midrange
Like the DT 770-80, the DT 660 suffers from a slight lower midrange suck-out. While this
effect seems to add more clarity because the overall sound appears to be less muffled, I think
this ‘muffling’ is what creates the fundament for the music. The upper midrange is
emphasized which gives the music a lot of forte and presence, especially on vocals.
Highs
The lower treble (around 3-5 KHz) is severely emphasized on this headphone, which at least
provides for a seamless transition from midrange to treble. Without doubt, this is one of the
brightest headphones I’ve ever come across. I think only the Grado SR-325 is brighter than
this Beyerdynamic. However, the DT660’s brightness is not necessarily a bad thing if you like
it. I actually did and this is coming from a Sennheiser HD 650 person. However, I feel that the
mid and upper highs should have been more extended in relation to the lower treble. Cymbal
crashes hence have too much impact and seemingly not enough decay. Listening fatigue in the
treble is very dependant from user to user but I personally don’t find the treble very fatiguing,
especially compared to the Ultrasone HFI 650. Of course, there are songs where I just can’t
listen to these headphones but in the remaining time the DT 660 gives me a very uplifting
experience. Never too harsh and surprisingly little sibilance, especially compared to the
Ultrasone. Playing around with my EQ, I have noticed that sibilance is mostly caused by a
treble peak in the region somewhere between 8 and 11 KHz, hence more of a frequencyrelated issue and less of an inherent quality of the headphone.
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Balance / Transitions / Even-handed frequency response?
The transition from bass to midrange could be a bit better although it’s still handled in a more
linear fashion compared to the DT 770-80 due to the 770-80 extremely strong bass. You can’t
really say that this a balanced headphone because the lower treble is obviously emphasized
but I still find that the headphone sounds coherent in its own right. Once you see everything
under the banner of a bright headphone, it’s good. For improving the overall balance, I
suggest adding a 120 Ohm impedance adapter.
Resolution
Well, aren’t brightness and detailing completely different things? Well, I think I would lie if I
said that these two things are completely unrelated. Fact is, many people perceive details
better when the headphone is bright. Further, after using my parametric EQ to turn down the
lower treble, most of the resolution was still there. In this regard, the DT 660 is on par with
the best of the bunch.
Headstage / Soundstage
The headstage is slightly smaller than the size of the AKG. So it’s not really big. The
soundstage is what’s pretty good about this headphones since it definitely extends beyond the
headstage. Good soundstage width for a closed headphones and in particular considering the
proximity of the drivers to the ears. Soundstage depth is presented nicely. Further the auditory
space is quite continuous without an overly strong left-right separation. All in all, I am very
pleased with its soundstage. Usually, it’s a characteristic of closed headphones for the
soundstage to be limited by its headstage but in this case (and similar with the Ultrasone) I
really find that the soundstage goes away from the head. It might be exaggerated to say this
but my former Stax SR-404 offered me a similar experience: little headstage, good
soundstage.
Visceral Impact/Attack
The DT 660 doesn’t have as much overall visceral impact as the DT 770-80 (mostly due its
bass) but its speed and punchy bass make up for it. A very crisp sound without being overly
edgy. Hard and fast hitting transient attacks. Sharp!
PRaT
Now, this headphone is all about PraT. If you don’t start moving your toes to this headphones,
you must be having knee problems.
Balance / Even-handed frequency response / Tone / Sound signature
This headphone constantly reminded me of a good Gin Tonic. The problem is that the DT 660
more or less imposes his fast-paced character on the music played making it somewhat
unsuited for cozy and relaxed listening. Diana Krall’s ‘Deed I Do’ on ‘Live in Paris’
embodies what this headphone is all about: a whirlwind of rhythm, speed, crazy piano scales,
hard-hitting hi-hats and a grooving bass.
Vocals / Instruments:
What surprised me is that vocals don’t sound off despite the lower treble hump. Just more
lively, perhaps a little thin with male vocals but who listens to male vocals anyway… Male
vocals lack the authority in the lower octaves. Guitars sound lively, piano sounds lively,
almost everything sounds lively. Sax is really hard to get right and sounds a bit thin on the DT
660 with little lower body. Piano is well done, lively but never overdone, drums are very good
despite the cymbals having a bit too much initial impact. Brass are violent but unlike the
Ultrasone, the DT660 brings out a more natural aggressiveness in them.
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Despite the brightness, vocals are only seldom sizzling or sibilant. Sometimes, the extra lower
treble gives vocals an airy and intimate touch.
The 120 Ohm adapter
In my opinion, the 120 Ohm adapter offers an serious improvement and with it, the DT 660
becomes one of my favorites for sound quality - right next to the A900, DT 770-80, DT 831
and AKG K271. It retains most of its former virtues (PRaT, uplifting experience) but removes
some of the excessive brightness. You get more bass (ok, slightly more bloated but who cares)
and more lower midrange. The 120 Ohm really does some magic to the balance and the best
part: you can always take off the 120 ohm adapter if you don’t need it. Unfortunately, you
lose the DT 660’s high efficiency.
Practical Considerations and Summing Up
There have been reports about the headband being prone to cracking but I did not encounter
this problem myself. Cable microphonics is none to very little.
Comfort-wise, the jaw-clamping factor can be something to be reckoned with. Two kinds of
pad material come with the DT 660: cloth and pleather. I found the cloth to be more
comfortable especially due to reduced sweating. The cloth used is not as soft as the velour
used on the DT 770-80. Despite the ear cups being big in area, they’re pretty shallow. Overall,
there are more comfortable headphones available but this is not too bad, especially
considering its portability.
Due to the DT 660’s emphasized treble and high efficiency, it is sensitive towards background
noise from Laptops or unclean headphone outs in general.
Given better amplification, there is an improvement although not as pronounced as with the
AKG K271. Probably around DT 770-80 level.
I think his headphone, just like AKG K181, fits nicely in-between the more portable DT 250250 and the stationary AKG K271, A900 and DT 770-80. Due to its high sensitivity, an amp
is not necessary unless you’d like to add the 120 Ohm impedance, which is highly
recommended but also makes an amp more more or less mandatory. For an exciting home and
semi-portable headphone, the DT 660 is an excellent choice in my opinion. Decent for both
gaming and movie watching. And if it doesn’t get your toes moving, I’ll buy you a Gin Tonic.
Beyerdynamic DT 770-80 Pro
Bass
These headphones are dubbed the bass monsters and with good reason. The bass is strong,
deep, fairly tight, and most of all with strong lower bass. However, one reason the bass stands
out is because the lower midrange is relatively subdued compared to the bass level. Further,
the DT 770-80 upper bass is not as strong which is another good trick to create the effect of a
strong low bass. Most of the overblown and bloated bass impressions derive from a muddy
upper bass / lower midrange as in the case of the Sony V6. The drawback to the DT 770’s
weaker upper bass / lower midrange is that certain instruments such as acoustic bass that need
a good upper bass to bloom don’t have enough body. While on the one hand, certain types of
music benefit from the perception of this increased “clarity”, others don’t and I’d prefer have
a headphone that simply gets the lower midrange right. Nevertheless, irrespective of these
issues, if you’re looking for the strongest bass without spending $1200 on the Grado PS-1,
look no further. Bass detailing is about average. Since the bass is pretty loud compared to the
45
rest of the frequency spectrum, sometimes the bass was all over the place where it shouldn’t
have been. However, all in all, the hype about the DT 770-80 being a bass monster might
have been overstylized. There’s a lot of it but the quality is slightly below average compared
to the other headphones in this review.
Midrange
The lower midrange feels sucked out but the rest of the midrange is averagely flat with a
slight and typical Beyerdynamician upper midrange emphasis.
Highs
As said, there is an increase in the upper midrange which goes over to a subtly increased
lower treble but then feels a bit recessed from mid treble onwards. Cymbals have a lot of
initial impact but lack in air, distinct tone and decay. A valid question is of course how
relevant highs above 5-7 KHz are since many recordings won’t make heavy use of these
frequencies. With normal pop recordings there’s plenty of treble to speak of. Of advantage is
that the DT 770-80 hardly sounds harsh or fatiguing in the highs.
Balance / Transitions / Even-handed frequency response?
Although there are no distinct colorations, I don’t feel that this is an overly balanced
headphone. Strong bass, strong upper midrange / lower treble, a recessed lower midrange and
a recessed mid/upper treble to finish things offs. Nonetheless, the imbalance is nowhere as
severe as on the Ultrasone HFI 650 and all in all, this can still be called a coherent sounding
headphone.
Resolution / Detail
Slightly worse than A900 and AKG 271 but good notwithstanding. The perception of less
details might also have been frequency dependant. One good thing about the DT 770-80 is
that details are well-integrated into the music and don’t jump at you as in the case of the DT
660 or HFI 650.
Headstage / Soundstage
The headstage is good. Smaller than A900 but bigger than all of the other closed headphones.
Imaging is good, not very holographic but more in a flat plane with average front to back
imaging. Left-right separation is not strong and the DT 770-80 creates a realistic phantom
image without the hole in the middle which I sometimes experience with the HD 25-1.
Compared to the headstage, the soundstage is only mediocre and doesn’t create a overly
convincing illusion of extension beyond the headstage, which might have to do with the
subdued mid and upper treble. All in all, the auditory space can be described as coherent and
never crowded. Compared to the other headphones, its headstage-soundstage is only second to
the A900. For gaming and movie watching the soundstage proved to be very satisfactory.
Visceral Impact/ Attack / Transients
Due to the well-developed bass, the DT 770-80 conveys a strong sense of visceral impact.
However, the DT 770-80 is not as fast as the AKG K271 when it comes to quick changes,
especially of those more subtle in nature. Similar to the A900 in this regard.
PRaT
Due to the emphasis in the upper midrange / lower treble, leading instruments and voices are
put into the spotlight with an underlining strong bass that provides the groove. Nevertheless, it
is not as uplifting as the DT 660 because of limitations in the treble. Further, compared to
really “pratty” headphones like the Grado RS-1, the DT 770-80 also has a touch of coldness.
46
Atmosphere / Tone / Sound signature
With the DT 770-80 I always felt an air of talking to a professional business man. Always
pleasant but not with enough emotion or treble. Difficult to love and hard to dislike. Like a
Lufthansa senator class lounge - spacious and down to earth. Just think Mercedes Benz
commercial with lots of bass.
Human voices / Instruments
I’m a fan of vocal sounds from Beyerdynamic headphones and the DT 770-80 makes no
exception: strong, serene, emancipated, lacks a bit of air but still crisp yet not edgy. The same
applies to the instruments, everything sounds a bit fresher and more upfront compared to the
A900 or AKG K271. Drums sound pretty cool with a lot of kick.
Emotional factor
With classical music it lacks a bit here. For example its rendition of the Kreutzer Sonate
doesn’t create enough tension and intensity of the highest harmonics in the violin and the
slightly subdued lower / mid midrange does not lend itself to adding a romantic touch to the
music.
Listening fatigue
This is probably the only headphone where listening fatigue does not come from the treble but
the bass.
Practical Considerations and Summing Up
Personally, I have a big head (9-10 clicks on the HD 650 on both sides) and for me the
headband did not extend far enough to make me feel perfectly comfortable. Clamping force
was medium to provide for sufficient isolation. The velour are extremely sweet and raises the
comfort level pretty high. Moreover, the voluminous ear cups leave a lot of space between the
ears and the drivers so that only the soft and cushy velour was touching the skin of the head.
Comfort is definitely high with the right head size. For the same reasons, you can use glasses
with the DT 770-80. If you don’t care for isolation, you can spread the headband to alleviate
clamping force even more. Due to its solid metal headband, you won’t have to be afraid of
breaking something.
No problems with cable microphonics. You may need to experiment a bit to find a good
position on the head. A good seal is necessary for bringing out the bass. Build quality is
outstanding with the already mentioned solid metal headband and scratch-free ear cups. The
velour pads are exchangeable. General throw-around-ability is very high. Probably as close to
indestructibility as you can get with headphones.
It won’t take a $1000 amp to make these sounds good but a decent amp is necessary to
provide enough volume and for enabling more bass impact, better bass control, a bigger
soundstage and better resolution overall. It is not scaleable as the AKG K271 but an amp is
recommended. You don’t buy these headphone and then skimp on the bass.
I have had the opportunity to compare the DT 770-80 to the DT 770-250 for about half an
hour and found that the DT 770-80 sounds more coherent and less scratchy in the highs. Both
are about equally hard to drive regardless of the different impedance ratings.
I think all in all, this is a very accomplished headphone with its main assets being the high
comfort, good soundstage, a big bass and a non-intrusive sound overall. From the headphones
tested, I found it to be the best for movie watching (tied with A900 here) and gaming. The
Ultrasone is also good for gaming but its lesser comfort and inability to sound good with
47
music (compared to the DT 770-80) makes it less of an overall performer for pure stationary
use.
Beyerdynamic DT 83122
I recommend the use of a 75 or 120 Ohm adapter for this headphone. It sounds good without
but even better with one. Considering that as for a more stationary headphone, efficiency is
not a big issue, I don’t see how you can go wrong with getting such an adapter for less than
$20 including shipping or self-made.
Bass
The DT 831’s bass took me by full surprise. The only thing I’ve ever heard about the DT 831
was its supposedly bright treble but never did anybody mention this headphone’s outstanding
bass. Yes, we’re almost talking DT 770-80 level type of bass. From a portable player, the DT
831’s bass does not have the DT 660’s tight punch, the AKG K271’s speed, the A900’s cozy
feeling or the DT 770-80’s bass madness, but rather a spot somewhere in-between all these
characteristics. Basically, it can be described as a DT 770-80 bass with slightly less impact.
Sometimes it can sound a tad soft but the depth and impact of the bass is very impressive. The
positioning of the headphones proved to have an influence on the bass presentation. I can only
emphasise again that for bass impact and depth, the DT 831 was only second to the DT 77080. Very groovy.
However, use a good source and a decent amp and the DT 831 will show you what real bass
is. For the first time in this review, I have to resolve to some bigger superlatives because when
I first connected the DT 831 to my MG Head, I was totally baffled of what the DT 831 was
capable of outputting: Deep, tight, fast and strong. Better than my Sennheiser HD 650. Still
not as much as the DT 770-80 in quantity but higher quality in my opinion. Is this the best
bass of all the headphones reviewed here? You bet.
Midrange
The midrange is where I have some gripes about this headphone. Just like the DT 770-80 the
DT 831 exhibits a midrange recession in the lower midrange which at times renders the music
a bit cold and lacking a warm underground compared to the AKG K271 or A900. What the
DT 831 lacks is an organic character in the midrange and more body.
Treble
The DT 831 is said to be very bright and while I don’t think it’s as bright as the DT 660, it is
still quite bright compared to all other headphones from this review. While certain passage
might sound overdone, the treble is usually not fatiguing due to a very resolving and refined
upper end. After listening to the DT 831 for several days, I acclimatized myself to the DT
831’s brighter presentation and found it very easy to enjoy this headphone’s uplifting
presentation. Unlike the DT 660, the DT 831 does not always sound exciting or toe-tapping
but is more versatile in its rendition of various musical styles and tempi. Frankly, while other
people might consider the treble a weakness of the DT 831, I think it can be both strength and
weakness of the DT 831 depending on how you like it.
Sibilance can be strong and annoying sometimes but it was rather recording- and sourcedependant. Unlike the DT 770-80, the DT 831 has a better treble extension in the mid and
upper treble making cymbal crashes sound very natural with a long and detailed decay.
22
Added on March 10th
48
Soundstage
This another strong suit of the DT 831. There’s not much to say about it other than that
imaging, size, depth, spatial separation, soundstage consistency were all very good. It has a
better soundstage than the DT 770-80 and K271 and while the overall soundstage size is
slightly smaller compared to the A900, the DT 831’s sound field sounds more open whereas
the A900’s soundstage has more “audible” borders. Excellent soundstage for a closed
headphone in this price range.
Resolution
The DT 831 is a very resolving headphone and while I’m not able to directly compare it to the
A900 or K271 anymore, I would say that they’re all on the same level. Due to the DT 831’s
bright presentation, however, certain musical nuances were pushed more strongly onto the
stage than was the case with the A900 for instance. I didn’t always like this fact and found the
A900 or K271 to be more natural in this regard.
Visceral Impact / Transients / PRaT
If you’re looking for a visceral sensation, this headphone delivers. Strong bass, blistering
highs - need I say more? The transient response is not quite as fast as on the K271 but still top
tier along with the A900 and DT 660. For the highest quality of PRaT, the DT 831 would
have needed a touch of idiosyncrasy in the midrange and a faster transient response, but all in
all, it was one of the “prattiest” headphones tested especially when the music involves lots of
bass. In fact, the DT 660 and DT 831 were those that had me dancing around the most.
Human Voices / Instruments
I expected certain instruments to sound overly bright or simply off but that was not the case.
Piano, guitars, drums and even saxophones or violins all sounded right. They might not
possess the smooth qualities of a K271 or A900 but are more exciting in exchange. Vocal
music is definitely made for the DT 831. The DT 831 retains some of that magic which the
DT 880 had on female vocals: airy, emancipated and with touch of sweetness. Male vocals
sounded very poised, dry and simply excellent, too.
Nevertheless, compared to the A900 or the Sennheiser HD 650, for certain songs the DT 831
did not have enough smoothness for certain musical subtleties like an aspirating sigh to reveal
its full potential. All things considered, I think the DT 831 has the best vocal reproduction out
of all the Beyerdynamic headphones in this review and that alone says a lot. A gospel choir on
this headphone is something that needs to be experienced.
Listening fatigue
Despite its bright characters, I can listen to this headphone for hours. However, if you mainly
listen to heavy metal with a lot of screaming voices, the situation might be slightly different.
Sound signature
The DT 831 is not what you’d call a cosy refuge for stressed ears although it isn’t a DT 660
rollercoaster ride either. While the DT 831 can be relaxing with the right type of music, this is
certainly not its strongest domain. When listening to this headphone I had the feeling of
entering a white, spacious and well-lit hall, which in spite of its pompous makeup does not
give a detached or imposing impression but rather one of cordial respect. However, it doesn’t
quite feel like slipping into a pair of comfortable and well-worn shoes like the A900 or K271
sometimes feel like. A rather cold-sounding headphone marked by clarity.
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Practical Considerations and Summing Up
The coiled cord is not what I would consider ideal for home use and the long-term is
somewhat compromised by the clamping force that is a tad stronger compared to the DT 77080 and especially attacks the jaw. Other than that, their comfort is similar.
This is also a very good gaming and movie headphone due to its strong bass, good soundstage
and precise imaging.
So why doesn’t this headphone get more attention? For one, people usually get scared when
they hear “bright” but the DT 831, as well as the DT 660, shows that there’s nothing to be
scarred of. And I’m saying this as the owner and long-time fan of one of the darkest
headphones on the market, the Sennheiser HD 650. Another reason is that bright headphones
sound especially bright when put into a A/B comparisons with other headphones.
Unfortunately, A/B comparisons are very often the only means of quickly deciding between
headphones at the local electronics store or headphone meets. Furthermore, the DT 831 does
not have any selling points like the K271’s alluring midrange, the A900’s fairly threedimensional soundstage and high efficiency, or the DT 770-80’s thunderous bass. The DT
831’s distinguishing trait is its bright presentation by what we would be back to square one.
Frankly, its technical capabilities are outstanding, it’s tonal balance is an acquired taste. I
expected nothing out of this headphone and my initial impressions were less than spectacular
but given some time and paired up it with a 120 or 75 Ohm adapter, I was rewarded with one
of the best-sounding closed headphone for under $200. The DT 831 is also a very good pair of
headphones for low-volume listening.
Certainly, the DT 831 is not perfect: The long-term comfort could have been better, there
could have been more warmth in the midrange, Beyerdynamic should have designed this
headphone with an 120 Ohm resistance “pre-installed”23 and occasionally I was wishing for
less overall treble. Sibilance was an issue with less than ideal players and recordings but
hardly something to fret about on a good system with most decent recordings. The DT 831 is
probably not the ideal headphone for volume crankers either because it’s probably too bright
for that.
Most of the time I was simply enjoying the music out of this remarkable closed headphone
and it easily deserves a place among the best in its price class. It could serve very well as a
secondary headphone if you need an spirited and awe-inspiring experience from time to time.
Audio Technica A900
Bass
Personally, I found the bass to be a rather strong point of the A900 but your mileage may
vary. It was not as tight as on the AKG but there was just more of it, especially lower bass.
When driven from a portable source such as the Ipod, there was more bass quantity and
quality than any of the other headphones provided. Bass decay could have been a bit better
but let’s not be overly picky here. The A900 does create a moderately woollen feel to the
sound but not to the extent of sounding muddy or undefined, just like a slight blur around the
bass contours. The transition from bass to midrange is managed really well, probably the best
among all the headphones tested.
23
It is indeed possible that Beyerdynamic designed the DT 831 with a headphone amp output impedance of 120
Ohm in mind because 120 Ohm used to be old standard whereas 0 Ohm is the standard of nowadays. Before 120
Ohm it used to be 600 Ohm.
50
Midrange
The lower midrange feels thicker and some may say more syrupy than on other headphones.
Personally, I found this to be a good thing as the bass and lower midrange provided me with a
solid foundation for the rest of music to base on. As for the rest of the midrange, it was
somewhat recessed and like the Sony V6, the overall frequency response was a bit bowl-like.
Lots of people find the lacking midrange to be the main criticism point about the A900 and I
have to agree.
Highs
The highs were pretty good on the A900 except for some glare here and there. I did not find
that particular frequencies were emphasised but due to the subdued midrange level, the
overall treble can be described as emphasised. However, this is by no mean a very bright
headphone. Treble extension was very good and as good as the DT 250-250 in this regard
albeit not quite as good as the AKG K271. There was little sibilance or listening fatigue with
the A900.
Resolution
The resolution of this headphone is surprisingly good even when faced with non-ideal
sources.
Headstage / Soundstage
This is a very strong aspect of the A900 because it clearly had the most superior soundstage
from the headphones reviewed. Both soundstage depth and width are excellent it listening to
the A900 feels like sink into a big, comfy couch. Literally seen, this is also the case
considering the excellent comfort.
Visceral Impact / Attack / Transients
The A900 is not as fast as the DT 660 or AKG K271 but closer to the DT 770-80 in this
regard. The attack is strong but without sounding forced. Supported by the solid bass
fundament and resolved highs, drum solos were very visceral. Of course, talking about
visceral impact with headphones is euphemistic but compared to the other headphones, the
A900 did very well.
PRaT
PRaT is good. There’s some solid bass to get the groove on and the treble did not skimp either
by providing plenty of rhythmic cues. Above average.
Balance / Even-handed frequency response / Tone / Sound signature
With the A900 I usually felt like sitting in a smoky New York jazz joint with dim lighting, a
cosy atmosphere and skilful musicians on stage. The enveloping soundstage manages to draw
you into the music with a matter-of-course attitude and this is exactly the sound I look for
when coming from a stressful day. However, unlike the DT 250-250 the A900 manages to
present exciting music equally well while its considerably laissez-faire attitude remains.
Despite its treble emphasis I find the A900 to be a warm-sounding headphone mainly due its
prominent bass and lower midrange.
Human voices / Instruments
An recurring observation has been that with certain vocals it sounds as if certain frequencies
were subdued. There’s body and top end but the middle part felt cut out leading to a dark yet
marginally sizzling presentation. In any case, most vocals take a step back from the stage and
sound slightly more distant.
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Summing Up
The A900 is the no-hassle-good-sound headphone and jack of all trades on top of that. It
sounds surprisingly good out of anything and with anything - be it movies, games or music but does not need to shy the DT 770-80’s or K271’s competition when faced with better
equipment to boot. Driven by a mere Ipod, the A900 might as well be the best-sounding
headphone I’ve ever heard, beating acclaimed open alternatives like the Sennheiser HD 600
or Grado SR-225 which revealed their need for an amp more strongly than the A900. The bass
could use some more definition and the midrange requires some lifting. Other than that, this
headphone sounds great.
If your source is a mere laptop soundcard or an Ipod and if don’t plan on purchasing a
headphone amp or a better source at any point in the future but still wish to attain the luxury
of an audiophile sound coupled with great comfort, then I suggest you look no further than the
Audio Technica A900. The fact that the A900 is also closed and can be used at the office
without disturbing colleagues - save for one or two glances at the alien technology looking 3D
wing headband system - is just another greatly appreciated bonus.
AKG K271 Studio
Bass
Let’s start right off where this headphone’s Achilles Heel lies: the bass. Some people say it’s
anemic and completely lacking, some say it’s just merely defined and tight. Personally I’m
tending towards the first group although I can see second group’s points. First of all, the bass
doesn’t reach very low or perhaps the lowest bass is attenuated - all the same if I can’t hear
them most of the time24. The proponents are right by saying that the bass is tight (probably the
tightest out of the bunch), but then you could also say that it’s simply overdamped. There’s
little bass fundament when there should be, there’s no bass slam, no walking bass line that can
be heard over the rest of the music. It’s a hifish bass if you will but it’s just not enough for
me. Sometimes it’s ok: Holly Cole on ‘I can see clearly now’ does not have as much bass as
I’m used to from other headphone but instead, her voice is given center stage. However, take
Tchaikovsky’s 1842 overture on Telarc with its famous digital canons: The only way to
describe the bass would be anemic.
Nonetheless, two things need to be in the bass’ favor: You won’t find such a refined bass
from any closed headphone in this price range meaning there’s absolutely no muddying of the
midrange. This can be a double-edged word though. For instance, on a deep acoustic bass you
will above all hear the notes’ pitch25 and melody line rather than the bloom or true
“deepness”. Secondly, you really get used to the amount of bass and most other headphones
will sound like bass monsters in comparison. To be honest, most of the time you just don’t
care about the bass if you can have the midrange.
Midrange
This is the where the headphone rises. Some say it’s colored and humped, some say it’s the
most beautiful midrange one can get from closed headphones (under $200) and that most of
our listening takes place in the midrange anyway26. I leaning towards the second group
although the first group has its points. The midrange is indeed a bit humped compared to the
24
With expensive amping, the lower bass receives more attention but still not to a presence level which the A900
or DT 770-80 offer
25
principle of missing fundamentals
26
The latter argument can be applied to any headphone with a midrange that pleases
52
other headphones. Not the lower midrange like the A900, not the upper midrange like DT
770-80 – but just the middle midrange. It sounds a bit like the pop-preset on my car stereo,
like an inverted U in the frequency response. Vocals come up front whereas the bass and
treble take a step back. Where the Sony V6 and A900 have a valley, the K271 has a small hill.
The only caveat is that the upper midrange could be a bit more prominent at times. Vocals
don’t have as much brilliant forte as the DT 770-80, DT 250-250 or DT 660 have. But it feels
almost more natural this way. Nevertheless, due to the humped midrange, there’s also a
slightly nasal character to the music at times, saxophones for instance.
Highs
The treble is well extended and detailed. The treble of this headphone, I dare say, is just
indisputably good. Indisputably because it’s really about technical capabilities here whereas
the midrange is more about the tonal character. Slightly rolled on top but delicate, snappy and
not sizzling, crisp and precise. Nice balance between all parts of the treble, no overdone lower
treble nor too much upper high end. It’s relaxing but gives you all the necessary treble
information at the same time. Definitely the best highs in the bunch along with the DT 250250 in my opinion.
Resolution
The AKG demonstrates nicely what resolution means as opposed to brute detailing. You can
hear everything but it’s all blended in nicely with the musical flow. Nothing jumps at you like
on the DT 660 does. Both macro- but especially the micro-detailing are done well. Most of
the subtle changes within the music that carry most of the emotion are conveyed pleasantly.
This is a very transparent headphone despite the colorations in the midrange 27. Everything is
heard with precise imaging and fit into a relatively small but well-worked out soundstage.
Given proper amplification28, the AKG will outrun all other headphones from this review in
resolution.
Headstage / Soundstage
The headstage is not as good as the A900 or DT 770-80 but things are placed in a more
structured manner than the Beyer does. Soundstage width is more narrow but it doesn’t feel
too cramped. Soundstage depth is a bit better than the DT 770-80 but not as good as the A900
or not as holographic for that matter. The soundstage extends slightly beyond the headstage
but not much. Overall, it is on par with the DT 770-80. Imaging is good.
Visceral Impact/Attack
This is another issue with the AKG 271: It is very fast but the notes don’t have a lot of attack.
Of course, it’s also less fatiguing but at the same time not quite as “bitey”. It’s about taking
the trade-offs here and I have to say that for long term listening the AKG’s trade-off might be
worth it.
PRaT
This is not the most toe tapping headphone, more like a sophisticated brandy drinking at a
gentleman’s club although that might take it a bit too far.
Emotional factor
A violin solo doesn’t grab me as much as it could but the AKG has a soothing and pleasing
character which lends the notes a tender and soft aura.
27
Head-Fi member Hirsch described the difference between accuracy and transparency so accurately with a
window analogy: Accuracy is the colour of the window, transparency is the cleanliness of it. A window can be
orange but very clean nonetheless.
28
Think at least $150-200 amp
53
Transients
Quick changes in volume, also at low volumes are rendered very well. Quick and precise with
excellent micro-dynamics.
Balance / Even-handed frequency response / Tone / Sound signature
I can’t help it but to keep associating the color orange whenever I listen to the AKG and when
I think of that I get thirsty thinking of a cooled orange flavored tea. Whereas the AKG 271
sounds relatively slick, the A900 sounds more chalky.
Human voices / Instruments
Vocals are done really well. They sound pretty realistic, perhaps a bit colored towards the
warmer spectrum. Warm would be too much and ‘golden’ might be more appropriate here.
Most instruments are rendered nicely although aggressive instruments such as brass or
distorted guitars sound a tad too “domesticated”.
Listening fatigue
The least listening fatigue from all the closed headphones despite the excellent resolving
capabilities and well extended highs. No sibilance to speak of.
Practical Considerations and Summing Up
The AKG definitely needs an amp to sound at his best. Without an bass, you can forget about
the bass even more and there might not be enough volume overall. In terms of scaling, the
AKG K271 showed the most capabilities and improved nicely with better equipment. A very
pleasant combination was the AKG K271 with the Earmax Pro, a $650 tube amp. Provided
with a better back end, the AKG K271 was technically superior to both the A900 and DT 77080. Of course, all the hifishness will be futile if you don’t like its tonal character. However,
the AKG is also quite EQ-able and having a software parametric EQ is one way to resolve
possible frequency issues.
The K271 has an auto-mute special which means that the headphone mute itself once you put
the headphone off your head (same mechanism like in a fridge).
All in all, the AKG K271 is not a beginner’s headphone in that is requires some dedication
and investment to get the sound right. Yet for a office or transportable rig, this can be an
excellent headphone. Wonderful sound quality and comfort paired with decent isolation -what else could you ask for? Well, perhaps more bass.
2.4 Conclusion
Unfortunately and probably as expected, no headphone is a clear winner. The Sennheiser HD
25-1 is highly portable but canalphones are more portable. And for sound quality, there are
better options, too. For every headphone, there are compromises and it’s mostly about finding
the right compromise.29
29
Re: Portability - Sound diagram. Personally, I prefer the Etymotic ER-4S over the Sony V6 for sound quality
but canalphones can be more of an acquired taste and they do have certain drawbacks in the sound department
compared to full-sized headphones.
54
Tables and Diagrams
Diagrams and tables are double-edged swords because whereas they are often descriptive and
time-saving, they can only convey part of the full picture in simplified form. It is therefore
strongly advised to use them in conjunction with the actual review text to avoid
misinterpretations
A900
No
1
5
10
K271
Yes
2
7
9
DT 770-80
Pro
Yes
3
6
9
DT 660
No
5
Yes
5
6
HD 280 Pro
No
4
Yes
8
5
DT 831
Yes/No
3
5
8
Need an amp?
Portability
Foldable
Isolation
Comfort
DT 250-250
Yes/No
6
3
7
HFI 650
No
7
Yes
7
5
V6
No
7
Yes
5
5
HD 25-1
No
8
7
4/531
HD 201
Yes/No
7
4
6
E3 / ER-4P/S
Yes/No
10
10
9
Need an amp?
Portability
Foldable
Isolation
Comfort
K 181
Yes
4
Yes
7
5
K 81
No
8
Yes
6
6
FC7
No
8
Yes
4
7
30
Need an Amp?
Portability
Foldable
Isolation
Comfort
30
This is my personal opinion. If you listen to your music at lower volume levels, you might not need an amp.
Please also refer to section 3.3 “Volume Testings with Ipod”.
31
Higher comfort with velour pads.
55
Recommended Applications (Gaming, Movies, DJ, Mixing, Portable, Semi-Portable,
Home)
Gaming
For gaming, the HFI 650, DT 831, A900, and DT 770-80 all did very well. The Ultrasone
might have had the slight upper hand in terms of imaging but the DT 770-80 is more
comfortable and other than for shooters where pin-point accuracy is essential, the DT 770-80
would be my first choice. The same applies to the A900 although I really liked the enhanced
bass impact an emphasis of the DT 770-80 when it comes to gaming. The DT 831 would be
tied with the A900 and the Sennheiser HD 280 presents a cost-effective solution. I reviewed
the AKG K 181 at a later time but given its nature and based on my Quake 4 testings, it is an
absolutely excellent gaming headphone and it also looks the part.
Movies
For movies, both the DT 770-80 and A900 are my top choices, the DT 831 a close third. It
then becomes a matter of where other priorities lie such as a more impactful bass performance
(DT 770-80) or for instance a more enclosing and three-dimensional soundstage (A900).
DJ
I am not a DJ myself but I think both the HD 25-1 and HFI 650 would be excellent DJ
headphones due to their high isolation, strong bass, flip-able / swivel-able earcups and
professional looks. In fact many professional DJs use the HD 25-1. The HD 280 might also be
an interesting and lower-priced alternative due to its very high isolation, fairly flat sound and
foldable ear cups as well. The same considerations apply to the Sony V6 although the
isolation is somewhat weaker compared to other three aforementioned options. Considering
the practical functions of the K 181 (mono/stereo switch), swivel-able cups, bass boost
switch) and its great sound, I also highly recommend this one.
Mixing
Let’s examine two headphones first. I could not imagine mixing with the AKG due to the
little bass because I would mix too much bass into the mix and the in my opinion coloured
midrange. The opposite applies to the Sony V6, which I found unbalanced and bass-heavy
with subdued mids. Interestingly, these two are among the most renowned headphones in the
studio industry with the AKG having won many awards and the Sony V6 a.k.a. 7506 in its
studio form being a long-time standard. What this tells me is that my recommendations for a
studio headphone would be very close to useless.
Some headphones are diffuse-field equalized, others are free-field equalized, others are
equalized by ear. I personally think that diffuse-field-equalized headphones will probably
make for a more natural sounding mix as it resembles the sound of speakers more closely. On
the other hand, a highly regarded sound engineering headphone, the Grado HP-1000 are not
diffuse field equalized as far as I know. Some headphones might make the music sound “too
good” although the same discussion can be found in the recording industry with people
complaining about certain tweeters sounding too sweet.
It is possible to hold an almost philosophical discussion this issue once we enter the realms of
topics like flatness and neutrality and the full extent thereof would clearly exceed the
boundaries and purpose of his short sub-section.32 In any case, I think it is not no big news
that the most important aspect in mixing to know how a mix transfers to the final record, i.e.
how it will sound in the average Joe’s listening room or headphone setup in the end. And that
32
This Head-Fi post answer many of the questions if you are further interested.
56
knowledge can only come with a lot of mixing experience with a particular pair of
headphones or speakers.
There is no standard solution and this is what mixing engineers mean when they say "Learn
your tools, their failures and their strengths and learn to do your work regardless of them; the
audience speakers will be different".33
Portable
In the highly portable field, the HD 25-1 remains my unreserved number one recommendation
if you have the necessary budget. I think on paper the HD 25-1 does not have many more
advantages over its competitors but it really fits a key niche with its decent looks, appropriate
size, good isolation, high efficiency hence eliminating the need for a portable amp and solid
sound quality with a bias towards the bass, which is something I highly welcome in portable
situations.
If you’re on a tighter budget, the AKG K 81 is all you need unless you can’t stand bass. Great
sound in a portable package, period.
The Ultrasone scores with its gaming qualities, more exciting but at the same time, for me
personally, more fatiguing sound signature and circumaural design. It does keep your ears
warm in winter.
The Sony V6 used to be the cost effective solution if bass matters and the HD 201 if not. The
introduction of the AKG K81, however, changed the dynamics of bang-per-buck on the go.
Regardless, the HD 201 deserves an award for having achieved almost audiophile-grade
sound quality for merely $20.
Canalphones obviously represent an excellent alternative in the portable field. This is will be
discussed in further detail in a later chapter.
Semi-portable
The DT 250-250 does not quite reach the comfort level of the stationary headphones and the
DT 660 can be more of an acquired taste due to its bright presentation. However, both the DT
250-250 and DT 660 are more portable in nature with the DT 660 not needing an amp and
having its foldable ability but being bigger in size and the DT 250-250 being smaller in size
but in need of an amp and without the ability to fold. Furthermore, one also has to consider
their different types of sounds - the exciting DT660 and the contemplative DT 250-250. The
AKG K181, in my opinion, offers a more balanced sound than the DT 660 while retaining the
necessary PRaT and impact compared to the DT 250-250. It is arguably the best-sounding and
most portable headphone out of these three semi-portable headphones but at the same the least
comfortable as well, especially in the long term and in summer.
Home / Office
When trying to decide between the A900, DT 770-80, DT 831 and AKG K271 it becomes
relatively easy when an amp is out of question in which case the A900 would be my number
one recommendation. However, the more sophisticated the associated equipment (both source
and amp) becomes, the more it will depend on personal preference.
33
Quoted quote from footnote above. For more information on mixing with headphones, please refer to the
following links:
http://headwize.com/articles/mixing_art.htm
http://headwize.com/articles/lxh2mix_art.htm
57
The DT 831 is definitely the dark horse of this review. It arrived late to the game but left a
very huge impression. The Beyerdynamic sounds stunning with classical music and its bright
sound only rarely was a disturbance. On the contrary, more often it proved to be an essential
part of my musical enjoyment and unlike the DT 660, the DT 831 can chill out as well. In
conjunction with the 120 Ohm, the DT 831 has proved be a very strong contender.
The DT 770-80 has an reputation to uphold and it does so splendidly by providing me with
the biggest bass I’ve heard out of any headphone under $1000. Add its fairly balanced
midrange and treble and you have a serious contender for the stationary use award.
The AKG K271 is the most sophisticated one out of all headphones tested and started
showing off its audiophile qualities with improved amplification and source material (CD
player, soundcard). However, lest we forget that this is also a very musical sounding
headphone with warm midrange characteristics and a very good upper end. And under these
premises, even the lack of a deep and strong bass can be forgiven.
Finally, we come to the A900, a real jack of all trades. It’s good for movies, gaming and
music; it is very efficient and comfortable, and offers decent isolation. The sound is hard to
fault either even though the midrange could have needed a lift. All in all, if you wish you to
have the best possible sound from a mediocre source (e.g. a portable player, cheap soundcard,
etc.) for home use and you don’t wish to buy an amp either, it becomes difficult not to
recommend the A900. But even when amped and put up against a stiff competition consisting
of a united AKG and Beyerdynamic front, the A900 can still hold its own.
I admit that I can’t seem to decide between these four closed headphones when it comes to
home use and that’s very true. Toss a four-sided coin and I’ll be happy to oblige with
whichever of these headphones gets chosen.
Musical Styles
I tried to avoid stating musical preferences for specific headphones in the review because I
find this to be a very subjective matter. Whereas some people prefer one headphone for rock,
others may prefer another. I think one way to tell which headphone might be the safer bet
would be by going by majority opinion even though it’s not the perfect way either.
Concluding Thoughts
Summing up, thanks a lot if you’ve managed to bear with me up till now. As you might have
been able to tell, I have more or less found a liking to all the headphones featured in this
review. In this regard, I find Wayne’s quote from Head-Fi to be particularly true:
“I've found that the best headphones are the ones I'm listening to at the
moment. They always sound better than the other ones that are just sitting
there. But then if you go by looks, the ones that I'm wearing at the moment
don't usually look too good unless a mirror happens to be nearby. But even
then my own rugged good looks tend to overshadow the headphones
themselves. My point? It's useless to talk about which are best. It all
depends on what you like.” - Wmcmanus
Honestly, they’re all good in their own way and as I have mentioned earlier, I would
recommend warmly to audition any of these headphone before purchase. The time spent on
hearing some headphones on your own cannot possibly be weighed against the time reading a
58
review like this, the former being much more precious and valuable, especially considering
that we’re not discussing truly high end audio where it’s not possible to audition the gear in
question. Due to a review’s inherent limitations of being confined in a world of silent ink (or
bits and bytes for that matter), it can’t yet beat a pair of individual ears. In fact, I wouldn’t
find it surprising if your conclusions were to differ greatly from mine.
59
3. Headphone-related Topics
In this chapter I will try to address a few headphone-related issues with relevance to the
review.
3.1 Canalphones vs. Headphones
In the beginning I was rather scared off the “canal”-part in canalphone. However, I’ve found
that they don’t actually reach as deep as I imagined them to, especially with the silicone tips
on the Shure E3 and the foam tips on both the Shure and Etymotic. The triple flange tips for
both Shure and Etymotics canalphones go a bit deeper and I can see how this might not be for
everyone.
Choosing between canalphones and headphones is above all choosing a satisfactory
compromise between sound quality, appearance, isolation and portability.
The following report is based on my experience from the Shure E2, E3, E4 and Etymotic ER4P/S. There might be canalphones that defy these assumptions.
Isolation
One of the main benefits of using canalphones is their incredible isolation. The attenuation of
lower frequencies in particular, which makes up for most of the noise in subways and
airplanes, is handled in a most accomplished fashion. Imagine sticking your little finger into
your ear canal as deep as possible and you’ll get an impression about the level of isolation
canalphones can offer. It is a very unique experience and may require some acclimatization to
this degree of acoustic insulation. There are people who do not like this reclusive aspect. Part
of the claustrophobic sensation is that you’ll be able to hear your teeth grinding among other
things. Further, not being to able to hear anything can be dangerous in road traffic.
“Canalphones are harmful to ears”
It is a myth to believe that because of the closer proximity to the ear drum, canalphones may
harm your ears more severely than normal headphones do. In fact, the opposite is quite true.
Due to the excellent isolation canalphones offer, it becomes dispensable to turn up the volume
in order to compensate for a high background noise floor. In portable situations I tend to listen
to canalphones at much lower listening levels than with normal headphones.
Nonetheless, what may be harmful to your ears is when the volume is accidentally turned up
too high. The more common accident is that mindless friends try to be funny by pulling out
your canalphones while you’re listening to them. A real world concern, however, is that
canalphones are not free of maintenance.
Canalphones require maintenance
One additional drawback to canalphones is that they are not as maintenance-free as regular
headphones are. There is both dirt accumulating from the inside, that is earwax, as well as dirt
coming in from the outside. Even if there’s no visible dirt, the warm and cozy atmosphere of
an ear canal provides an almost ideal breeding ground for bacteria. Therefore disposable
60
earwax filters and foam tips should be replaced on a regular basis. Silicone tips should be
washed at least once a week and certain canalphones have a “picker” for earwax that should
be consulted as one sees fit. Most canalphone manuals will go into further detail regarding
maintenance.
Size / Portability
The most important issue is the size aspect. With canalphones you can achieve excellent
sound quality while maintaining the size of a cheap Sony earbud and be blessed by marvelous
isolation at the same time. The low profile allows me to walk the streets of Zurich without
catching too many glances.
One drawback of canalphones is that it is much easier to get kinked cables. Since I usually
don’t put my canalphones back into their protective cases/bags in an ordered manner, I often
spend a minute or two de-kinking the canalphones from its cable.
Further, slightly more time is required for taking out and re-inserting canalphones than it takes
me to put the HD 25-1 around my neck and back on my head. It’s only a matter of a few
seconds each time but for certain applications, such as walking around campus, it can be
reasonably annoying.
Besides, in order to keep the canalphones clean, one should always put them back into their
protective cases or bags.
Battery Drain
Although I did not perform any timed tests, I had the feeling that battery life was longer with
canalphones than with some of the more demanding full-sized headphones. In any case, the
Sennheiser HD 25-1, Audio Technica A900, Sony V6 and Beyerdynamic DT DT660 with
their high sensitivity lived rather long as well.
Insertion / Wear
A good seal is absolutely mandatory for good sonic results. Most of the negative impressions
from canalphone are the results of bad seals leading to a thin and bass-less sound.
Admittingly, canalphones are not bass monsters to begin with but without a proper seal, the
balance between bass, midrange and treble will be totally off.
Secondly, it is important to know how to route the canalphone’s cable. The Shures are usually
routed over the back of the ear to allow for a lower profile and higher mobility whereas the
Etymotics are supposed to go straight into the ear. Personally, I also route the Etymotics over
the back of my ear.
Comfort with canalphones can vary strongly between individuals. Personally, I can wear them
for 2-3 hours until taking a short break whereas other people can wear them all day long.
Others again will pull them out just seconds after putting them in. However, if you think that
you might be able to live with these little creatures in your ears, than you most likely will.
A bit of manual reading and experimentation is necessary but a good seal and fit are
absolutely essential for a satisfactory canalphone experience.
61
Sound quality
This the most tricky part because opinions are widely divided on whether canalphones sound
better in general. Personally, I find that canalphone do not sound better than an equally-priced
headphones (not counting Bose and other overpriced products).
Even if canalphones supposedly provide the most direct way of music to our brain, it simply
doesn’t sound natural or realistic to my ears since normal hearing also includes natural
distortion provided by the outer ear (more on this in chapter 4). So unless the music industry
starts producing binaural recordings on a regular basis, I doubt that canalphones will ever
replace regular headphones for a pleasing listening experience.
Another issue is that some people might them more fatiguing over time. It might be a
combination of the perpetual close contact to the ears and small-staged sound that provide this
kind of listening fatigue. In this regard, the lower-priced and more muddy sounding E2 was
not quite as fatiguing. Personally, I can wear canalphones for hours without a problem, which
is a very useful asset during long distance travels.
Canalphones in this price range will never be able to produce the kind of bass that full-sized
headphones do. The bass might be tighter and refined but for me an inherent quality of bass is
‘slam’ and if that is missing, a lot is missing. While they’re not completely bass shy and one
gets used to it, every time I switch on the Sennheiser HD 25-1 or Beyerdynamic DT 250-250,
I can’t help but smile. I also don’t consider canalphones to be as toe-tapping or groovy as
their full sized counterparts.
Moreover, canalphones lack the headstage of headphones -- the musical picture frame is
smaller. However, the borders between “music” and “non-music” is more blurred on
canalphones. With headphones, there are fixed boundaries to the soundstage but with
canalphones I can sometimes trick myself into thinking that the music expands into the whole
wide world as if the soundstage knew no limits. I suppose that the latter phenomena is very
person-dependant and I do not know what deeper psychoacoustical reasons might play a role
here.
Going back to what I find unsatisfactory about the Shures and Etymotics. Sometimes it is said
that canalphones are more detailed. While it is true that the Etymotic ER-4S sound very
detailed, I’m not sure whether this it not simply due to a boosted treble leading to a mere
impression of increased resolution. When I tamed down the highs using a parametric
equalizer, some of that “resolution” went missing. The ER-4S still remains very detailed and
certainly as good as the best of the headphones in this review (AKG K271, A900,
Beyerdynamic DT 250-250) but I just don’t consider it more detailed. The Shure E3 on the
other hand is simply less detailed. For a closer comparison between the Shure and Etymotic
canalphones, please see chapter 2.4
Summing up, canalphones offer a quite unique listening experience but sometimes I’m just
longing for the “bigger” sound. I like listening to car stereos not because they provide me
with high fidelity but because of the “big” sound and whooping bass. The same goes for
headphones and canalphones. Your priorities may vary but a small soundstage, thin sound and
little bass slam are the opposite sound characteristics that I’m looking for in a portable
headphone.
62
Why the perception of canalphones might differ from user to user
The other day I met with friends to sample a variety of audio gear, which included my pair of
Shure E500 canalphones, which I’ve always found to be somewhat lacking in little treble
energy. Strangely nobody shared my concerns, at least not to the same degree. Marcel
intelligently noted that unlike with headphones, the sound of canalphones does not interact
with the outer ear and therefore isn't influenced by the head-related transfer function, which is
particularly relevant for the upper registers. 34 Summing up, I probably have a "bright ear".
Therefore I also disagree with some opinions that different ear shapes influence the sound of
canalphones due to fit issues, as it is rather the lack thereof that leads to an altered perception
of music.
Conclusion
Summing up, canalphones can be the traveler’s favorite accessory. I find it to be an excellent
compromise between sound quality and portability despite their few shortcoming in the sound
department. Sound quality, comfort and isolation are good enough for an airplane or train
passenger to blissfully sink into the music while remaining as portable you can possibly be. If
you’re not in need of extreme isolation or do not have any size limitations, then headphones
might be the better option as these usually offer a much better sound/price ratio. You’ll have
to judge for yourself whether the canalphones’ trade-offs are worthwhile enough.
3.2 Headphones: Cheaper Alternatives
Besides the headphones reviewed here, there’s a bunch of popular alternatives, which may
absolutely suffice for one’s listening needs. Please keep in mind that this is by far a
comprehensive list but rather a small compilation of headphones that I have heard or heard of.
Open Headphones
For open headphones, the Koss KSC-35 (or its successor KSC-75), Koss Porta Pro,
Sennheiser PX100 and AKG K24P35 are all competitive headphones in the $30-$50 price
range. The KSC-35/75 are “clip-ons” whereas the others use a conventional headband. Soundwise, these open headphones produce a more airy and effortless presentation than the Sony
V6 or Sennheiser HD 25-1 but ultimately lack in resolution or bass response which the HD
25-1 or V6 offer in plethora. Furthermore, they suffer from the infringements of open
headphones, that is sound leakage and absence of isolation. However, it needs to be said that
34
For readers who aren't familiar with the concept of HRTF (head-related transfer function): Suppose I hear a
piano in real life, the sound waves will pass through and interact with my outer ear in a way that the frequency
spectrum will be altered. A flat signal measured outside my ear will thus always measure differently if measured
inside the ear. The exact function is everyone's individual HRTF. With headphones, this effect is lessened but
still present. With canalphones, however, the sound does not undergo outer ear influences. Therefore,
canalphones need to be equalized to sound "right" at the entrance of the inner ear to begin with. This equalization
will most likely take place by simulating the HRTF of a standardized / average ear. Assuming my outer ear
usually alters the sound in a way that the highs are boosted - compared to the average ear and thus keeping it
neutral in my frame of reference - a canalphone would need to be brighter in order for me to perceive it as fairly
neutral. I have no idea how big the effect of this all is but it might explain my gripes about the E500's treble,
which stand in contrast to mainstream perception. For more information on HRTF, consult section “4.2 –
Psychoacoustical Influences”
35
I have only heard the Koss KSC-35 and Sennheiser PX 100 but the other offerings are said offer similar sound
quality
63
these headphones are indeed more portable due to their smaller size and less geeky looks. Due
to the little weight, they are also more comfortable than their bigger sized brothers. The AKG
offering is quite new whereas the Sennheiser is a bit older already and has already received
various design awards. The comparatively bass-heavy Koss Porta Pro on the other hand is an
established standard decorated with rave reviews from many audio magazines. Nevertheless,
it is the Koss KSC-35 which has the strongest following in the headphone community and in
my honest opinion, no other headphone offers a better cost/benefit ration than this little gem. I
still use it for jogging on a daily basis. If only it wouldn’t leak so much sound…
Closed Headphones
….Enter the closed headphones in the same size format: Sennheiser PX200 and AKG
K26P.36 Unfortunately, I found the PX200 to be less good sounding than the PX100 but I was
told that in order to achieve a good sound with the PX200, much depends on the seal between
your ears and the headphones. Others who have had a better seal reported about a strong and
powerful bass. But regardless of the bass, the PX200 simply did not sound as good as the
PX100 in other areas either. Aside from that, these headphones offer a great compromise
between sound quality and portability. They may not sound quite as good as their open
counterparts but they don’t leak sound either. Isolation is decent but not great.
Overall, the PX200 would be my choice for a very comfortable closed headphone that easily
fits into the pocket in its folded form and which offers a low-profile look for the self-aware
urban commuter or office guy who does not have sound quality or isolation as a top priorities
- while still sounding better than most of the choices you’ll be presented with at your
electronics store. Compared to canalphones, it has the advantage of being much more hasslefree and unlike the HD 25-1 a jacket pocket is big enough for storing the PX200.
Then there is also the lesser version of the Sennheiser HD 25-1, namely the HD 25 SP which
can be distinguished by its two-sided cable and non-splittable headband. From my brief
listening sessions with these, I would rank them about equal to the Sony V6. The HD 25 SP
has less overall bass and a more muddy high end than the Sony but offers a more balanced
sound in exchange. It also leans on the warm side of neutral.
Earphones / Entry-level canalphones
Finally, there is the entry-level canalphone represented by the Shure E2 for just $60-70 and
less on the used market. Sound-wise, it’s not as good as the Koss KSC-35, PX100 and
perhaps not even as good as the PX200 in the sound domain (I never compared these two side
by side) but its greatest asset is its ultimate portability. The entry-level canalphone from
Etymotics Research is the ER-6i (upgrade from the former ER-6), which, however, already
plays in the price region of the E3. To be honest, for what the E2 offers, it is hard to beat
(isolation, size, price, decent sound quality) - unless you don’t like canalphones or simply put
more emphasis on sound quality. The Sony EX-71, ATH-CM7 and Sharp HP-MD33 are
popular choices for earphones, which I have not heard yet.
36
I have only heard the PX 200
64
Conclusion
E2
KSC-35
PX200
I’m afraid there’s no perfect portable headphone and trade-offs need to be taken either here or
there. The three kinds of headphones from above offer great alternatives at a lower price than
the bigger sized headphones from this review, namely providing better looks, smaller size,
sometimes higher comfort and in the case of canalphones, also better isolation. The
compromises you have to take are lesser sound quality and also sound leakage in the case of
the open alternatives.
3.3 Amped vs. Unamped / Portable Headphone Amplifiers
When people say “amp” they usually mean an external headphone amp. Every portable player
such as the Ipod has an internal amp because otherwise there would be no sound at all. But
since sound quality is usually of secondary concern to issues like battery life and parts cost,
most portable players’ internal amps are less than satisfactory for audiophile needs. Same
goes for most headphone outs on tuners or integrated amps although there are good-sounding
exceptions, too. Therefore “amp” is just a convention for “external, dedicated, headphone
amp”. Also, if you have a normal home CD player with a standard RCA line out, you will
need a headphone amp just as you’d need an integrated amp/tuner/power amp for your
speakers. Headphones are like mini-speakers in a way.
“Easy to drive” / “Hard to drive”
What do the terms “easy” or “hard to drive” mean? It can mean two things:
1. Your portable player won’t provide enough sound volume when using a particular pair
of headphones.
2. There is enough sound volume but an external amp would significantly enhance the
sound quality.
Take the Sennheiser HD600 as an example. It is somewhat hard to drive but an Ipod can
provide enough juice for medium listening levels. However, sound quality is not nearly as
good as when being connected to an external amp. So, in the case of the HD 600 both points
would apply.
Easy to drive can mean that it either doesn't take a lot of power to drive the headphones or
that they don't scale a lot given better amplification or both.
65
As a general rule, headphones with a high impedance (above 100 Ohms) are in more need of
an amp whereas low impedance amps sometimes require an amp. “Sometimes” because most
of the cheap consumer level Sony ear buds also have low impedance (usually 32 Ohm). On
the other hand, higher end headphones with a low impedance (Sony CD3000, Grado
headphones, …) usually indicate a high current need whereas headphones with a high
impedance (Sennheiser HD 600, Beyerdynamic DT 880, …) require a higher voltage swing.
Since most portable players’ internal amps don’t handle either too well, an amp may be
necessary in these cases.
For understanding headphone power requirements, please refer to this link: Understanding
Headphone Power Requirements
Sensitivity is the key word. When looking for answers whether a headphone can be powered
from your portable player, look at the sensitivity ratings.
Adding an amp is sometimes necessary to provide a sufficient volume level but in most cases
it is about improving sound quality. However, a more “powerful” amp doesn’t imply that the
music will sound more pompous or overpowering. It will simply handle things with more ease
and matter-of-course attitude. A good amp can and should sound either pompous or gentle
depending on the music.
Volume Testings with Ipod
Source: European Ipod 4th Generation37. Michael Jackson - ‘Black or White’ encoded from
original ‘Dangerous’ album at 160 kbps.
Since I did not have an SPL meter, I could only use my ears for “measuring” the volume.
Further, the Ipod does not have an exact volume level reading but just a continuous bar
indicating the volume. Therefore these “measurements” are of highly approximate nature.
1 indicates an empty bar (no volume), 10 indicated a full bar (max volume)38
Shure E3
Etymotic 4P
Sennheiser HD 25-1 (reference)
Beyerdynamic DT 660
Sony V6
Audio Technica A900
Ultrasone HFI 650
Koss KSC-35
Sennheiser HD 280 Pro
Etymotic ER-4S
Beyerdynamic DT 831
Sennheiser HD 201
Beyerdynamic DT 250-80
Beyerdynamic DT 770-80
Beyerdynamic DT 250-250
AKG K271
4
5
6
6
6
6-7
7
7
8
8
8
8-9
8-9
9
9-10
9-10
37
Following European regulations, European Ipods have certain power limitations allowing for less maximum
volume, which other Ipods do not have.
38
This list does not include all headphones review as some of them were added at a later time.
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Is an amp really necessary?
For certain headphones an amp might be necessary (AKG K271), for others it is more of a
luxury (Beyerdynamic DT 660) and for others it’s more like a waste of money. The HD 25-1
for instance does not benefit very much improved amplification although the improvement is
not non-existent either. It all depends on how much you’re willing to spend for a limited
amount of audible enhancement.
Secondly, you’ll have to take imperfect listening environments into account, that is ambient
noise and other distractions, which even the best of amps will have to live with.
Finally, portable sources are not the epitome of high fidelity and will always remain a
significant bottleneck in the system. Some people alleviate this problem by adding an external
DAC to their portable rigs, which decreases portability even further at increasing costs. Yet
for a transportable office/home rig, this can be a good solution.
In what areas does an amp improve the sound quality?
There is a lot of literature on the benefits of amps and I can only try to provide a short
overview of what amps can do.
Basically, it’s a matter of improved control over the music. There might be a tighter bass, a
better soundstage, higher resolution, higher dynamical range (i.e. bigger contrast between
loud and quiet passages) and a more natural sound overall. The details sound more convincing
and are better integrated into the musical flow. Subtleties such as the decay of cymbal crashes
become more apparent without sounding harsh. In fact, there might be less perceived bass
because the amp gets a better hold of the original information on the recording leading to a
less muddy or even bloated bass. The attack of sounds will also improve meaning that the
plucking of strings, striking of drum sticks, short bursts of horns - or just about any fast
changes in volume - will have a stronger and more realistic, initial impact (transient
response). In the end, the music has to sound more realistic.
An amp will not alter the sound significantly and in fact, it shouldn’t. It’s more like
sharpening a picture in Photoshop (perhaps with slight adjustment in brightness and contrast)
rather than a change of colors. Of course the analogy is not entirely correct because
Photopshop cannot retrieve what’s already lost while the purpose of the amp is to save
musical information from being lost by a player’s crappy internal amp. The ideal amplifier is
a so-called “wire with gain”.
Nevertheless, one has to keep in mind that amp differences are very often marginal to begin
with. There have been various occasions when I’ve had non-audiophile people listen to my
headphones with and without an amp yet without any remarkable recognition for the amp’s
benefits.
What do I lose?
An amp reduces portability greatly and hence better suited for semi-portable applications such
as commuting or using headphones in stationary places. Even though nowadays’ amps are
becoming ever smaller, there will always be minimalists that even consider the smallest of
amps to be too cumbersome to bother with. And of course, amps are expensive ranging from a
$50 Cmoy to a $400 high end portable amp.
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It depends on how to set the following priorities: ‘price’ vs. ‘portability’ vs. ‘sound
improvement’.
Personally, I found that there were noticeable sound quality differences between the $400
Emmeline SR-71, the dated Porta Corda MKI (there’s already a MKIII) and the Ipod’s
headphone out. If it weren’t for the decreased portability, I probably would have kept the SR71.
What’s a reasonable spending limit?
Does it make sense to spend $100 on a 5% improvement? First of all, 5% compared to what?
Secondly, it is an improvement, is it not? Finally, does it make sense to spend $2500 on pair
of headphones? Maybe it does, maybe it doesn’t, but there will be people who think that the
improvement is worthwhile just as there’ll be people who will spend $100 on a 5%
improvement.
Some people walk around with a $200 player, a $300 external DAC, a $300 amp and $800
canalphones. Others are satisfied with a $100 player and $30 headphones and there’s a whole
spending spectrum in-between. There’s no fixed border although I would venture to say that
anything above the KSC-35 and Shure E2 level ($30-60) can be regarded as being heavily
affected by the law of diminishing returns.
To use a marginalist approach: It doesn’t matter whether the prior $100 might have brought
upon a more significant improvement. The starting point is now, not the past, and the issue at
hand is whether to move forward or not. After every upgrade there’s a new starting point and
you can repeat the upgrading process until you think that the necessary costs will outweigh
the added benefits. And as you can imagine it is hardly feasible to devise a rule or derive from
common sense as to when the added monetary costs will outweigh the benefits of personal
pleasure for every individual listener.
3.4 Headphone Cable and Misc
Headphone plug: Angled vs. Straight
An Angled plug uses up less space in your pocket and it can’t be accidentally pulled out
during portable use. Straight plugs are slightly better suited for use at home.
Cable: Coiled vs. Straight
I don’t really like coiled cables because they’re either too short and when you expand them to
a longer length, the spring force will keep pulling back on the headphones. It might be useful
for studio applications where a cable mess needs to be avoided but I don’t see any significant
advantages for both home and portable listening although for portable usage, the shorter
length may be desirable.
Cable Upgrades
First of all let me say that only audiophiles would actually bother with upgrading a headphone
cable. This is can be classified as the least important upgrade right next to upgrading
interconnects. But once you’ve reached a certain level with your source, amp and headphones,
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this is the about only way to further enhance and/or alter the sound. The fact that some
skeptics say that it’s all placebo should highlight the order of magnitude in sonic
improvement that we’re talking about.
Cable Upgrade: Sennheiser HD 25-1
The Sennheiser HD 650 is famous for its huge market of upgrade cables. At one point, HeadFi member JaZZ and I had a small headphone come-together when we discovered that the
cables for the HD 650 could also be used on the HD 25-1. Some months after having posted
this discovery, I’ve seen posts saying that upgrading the HD 25-1’s cable is absolutely
necessary. In my HD 25-1 review I went into a similar direction but my opinion has changed
somewhat since then. The HD 25-1’s stock cable uses steel as conductor type whereas most
cables use copper. I tried the HD 25-13 stock cable (copper) with some good results but the
headphone plug is 6.3mm so an adapter would always be necessary. Head-Fi member
NeilPeart has suggested using the Sennheiser HD 580 stock cable, which is made of oxygenfree-copper and conveniently terminates in a 3.5mm mini plug. The downside to this cable is
that it doesn’t make use of the HD 25-1/HD 25-13 cable’s single-sidedness with the user
having to invert the ear cups. This definitely reduces the HD 25-1 high grades in “around-theneck-ability” and “throw-around-ability”. Further, both cables are 3m long as opposed to the
HD 25-1 stock cable’s 1.5m, which is much more practicable for portable usage. Finally,
since I use the HD 25-1 for heavy-duty portable use, there’s always a lot of moving around
and outside noise so that the better cable’s miniscule benefits are easily cancelled out by the
lesser portability. The HD 25-1 is the single headphone that has shown me the biggest
improvements in changing headphone cables (due to its stock steel cable) but its main asset
portability had to suffer in exchange.
A more extravagant possibility is to let a professional person re-cable the HD 25-1 for you
according to your wishes (cable length, termination type, conductor type, sleeving). Headphile
offers this service but at expenses. However, these kind of aftermarket cables also won’t make
use of the HD 25-1 single-sided-ness. As Head-Fi member bangraman once pointed out, the
best solution would be shortening the HD 25-13 cable to an appropriate length and
reterminating it with an 3.5mm angled plug. This way you’ll have all the advantages of both
increased sound quality and unfettered portability. Nonregarding the latter solution, which I
will try out eventually, I’m rather pleased with the stock cable as a good compromise between
price, portability and sound quality.
Update: Some Head-Fi members have successfully experimented with routing the HD 580
cable inside the Hd 25-1 headband making this a single-sided cable solution as well. It doesn’t
look very pretty but if you want to benefit from a cable upgrade but don’t feel like touching a
soldering iron to reterminate the Hd 25-13 cable with a 3.5mm plug, the HD 580 cable might
be an interesting alternative. Please search the forums for specific instructions.
Cable Upgrade: Other headphones
The AKG K271 is another headphone where changing the cable is possible. As far as I know,
both Headphile and Zu Audio offer upgraded cables for the AKG K271. There may be other
manufacturers as well.
Finally, you can upgrade the cable on any other headphone even if the cable is not removable
as on the Sennheiser HD 25-1 and AKG K271. You can simply let an experienced DIYer or
Headphile “re-cable” it for you. Extravagant? Certainly.
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Serial Resistance Adapters (e.g. 120 Ohm or 75 Ohm)
Certain headphones like the Beyerdynamic DT 831 or DT 660 benefit from the use of a serial
120 Ohm adapter39 that is put in-between the headphone plug and the headphone jack. While
this reduces overall efficiency, which means the headphone becomes harder to drive, it can
also “correct” unwanted deviations in the frequency response and make the sound more
pleasant. Usually, you can foretell the effects of an added serial resistance by looking at a
headphone’s impedance curve.
For sound quality, I recommend using the 120 Ohm with the Beyerdynamic DT 660, DT 831
and Ultrasone HFI 650 mainly to tame the brightness and add some more presence to the
lower midrange. The Ultrasone, however, is an otherwise efficient portable headphone that
will most likely require an amp after adding the 120 Ohm resistance.
One reason the Beyerdynamic headphones might benefit from a 120 Ohm adapter is because
there used to be different standards for the output impedance of headphone amps. Nowadays,
close to 0 Ohm is the standard but some receiver jacks still have an output impedance of 120
Ohms. Headphones like the DT 831 might have been designed with an amp’s output
impedance of 120 Ohms in mind.
The Etymotic ER-4P benefits from a 75Ohm adapter or adapter cable and the ER-4S is in fact
just an ER-4P with an internally added serial resistance of around 75 Ohm.
The technical background behind adding serial resistance to a headphone has to do with
damping factor.
Damping factor
Some people say that high impedance headphones sound better because they have a higher
damping factor. The damping factor is equal to headphone's input impedance divided by
amp's output impedance. From my experience, I can't say I agree with the generalisation of
high impedance headphones sounding cleaner than low impedance headphones unamped as
this can vary from headphone to headphone and their specific power requirements and driver
design, and whatever is driving them.
From the technical point of view, it is true that lower impedance headphones will see a lower
damping factor which may or may not result in a looser, perhaps warmer bass. This will
depends on how prone the headphones is to damping. This is more an issue with receiver
jacks than with dedicated headphones amps that usually have an output impedance of close to
zero Ohms. Certain tube amps (e.g. older OTL designs like the MG Head) may not abide by
this rule and that brings in further problems with low impedance headphones, but that's a
different story.
To complicate things even further, certain headphones like the older Beyerdynamic designs,
DT 831 for instance, sound better with a high output impedance, i.e. lower damping factor.
Again, the driver's design plays an important role, too, so one really has to look at individual
cases. For instance, Grados apparently employ a lot of mechanical damping so that electric
damping doesn't have a big influence on the sound, which can be seen when you look at the
relatively flat frequency-impedance curve. However, that doesn't mean that Grados don't
sound better with a low output impedance nonetheless since with a higher output impedance
you also reduce the effective power transferred to the headphone. This explanation is a bit
39
I bought mine at Meier-Audio
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flaky since it's not really power transfer that matters but voltage transfer but hopefully you get
the point. The added output impedance acts as a voltage divider which is not what we want.
The electric component with the higher impedance gets most of the voltage so we want a low
output impedance and high input impedance. This applies both to the cdp-to-amp as well as
amp-to-headphon stages. To give one example: if output and input impedance are of the same
value, we basically lose half the signal.
Fact is, it all depends on how the headphone was designed and what kind of amp it was
designed for. You could go on and on as damping is a widely discussed topic in audio. A
google search would yield an abundance of hits.
As for volume level, impedance is just one side of the story although it's true that most of the
time low impedance headphones can go louder since most portable players cannot provide
enough gain for high impedance headphones, and most consumer level headphone are
standardized at 32 Ohms. On the other hand, the amp may not provide enough current for
low-impedance yet current demanding headphones like the Sony CD 3000 leading to a rather
anemic bass and other problem including the treble. And once you go into the low impedance
regions for headphones, you may also run into problems with undersized output coupling
capacitors found in a lot of portable devices, resulting in a bass roll-off as found on the older
Ipod for instance. This is one reason why a lot of people complain about a weak bass from the
Ipod because most consumer headphones have a low output impedance of 32 Ohms.
Bottom line: Don't worry about impedance too much because most of today's headphones are
designed for today's headphone amps and there are only very few exceptions. For more
information on damping factor, consult google or go here for a start: http://www.classicaudio.com/marantz/mdampingfactor.html
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4. Frequency Graphs and Reviewers scrutinized
This chapter was written with significant help from Head-Fi member Halcyon.
4.1 Frequency Graphs
To start off let me ask a simple question: Have you ever seen a reviewer using frequency
graphs (FG) to tell a story? They might try tell you something about a headphone’s or
speaker’s frequency response (FR) but not on the basis of reading FG but rather on the basis
of listening to them.
One must know what kind of conclusions and to what extent these conclusions can be drawn
from graphs. Most people don't know this and it is a heuristic skill that can only be honed by
listening and looking at graphs, side by side, for years and for many components. It also
requires understanding of basic audio reproduction errors and their audibility ranges (i.e.
understanding of psychoacoustics).
Sometimes, people look at FG and “know” how the headphone will sound like. For example:
“The graph is flat so the headphone must sound neutral”. In fact, the latter statement couldn’t
be farther from the truth.
FG Basics
FG shows the measurements of the sound waves amplitude (sound level) for each frequency
(wavelength). However, most transducers’ FR change with varying volumes, which means
that transducer sensitivity is not always linear throughout the frequency range. When one
combines this with the non-linear changes in human hearing sensitivity as a function of sound
pressure (see chapter 4.2), one starts to understand why it's difficult to measure and even more
difficult to compare measurements to listening results. Further, sound from reflecting walls
makes things even more complicated because it sounds more natural this way (nobody listens
to speakers in an anechoic chamber) but is also more difficult to measure. So when you have
headphone that is pretty much a highly reverbant chamber, things will get very nasty, very
fast.
If you measure a properly designed flat speaker at the entrance to the ear canal, the
measurement curve will not be flat. This is due to the torso, head and outer ears distorting the
signal naturally for all of us. This change from a flat to a non-flat frequency response at the
ear canal level is called the (outer ear) Head Related Transfer Function, and it tells us how a
signal already changes before the ear drum, where it is heard by a human listener. There are
also other transfer functions, like middle-ear transfer function and inner-ear transfer function.
Hence, when measuring a flat signal at the entrance to the ear canal - regardless of the source
(speaker/headphones) - something must have gone wrong, either with the measurement or the
source must sound like crap because it is not supposed to be flat.
A good headphone designer takes this into account and designs the headphone to sound best,
that is not flat, but ideal in terms of generic/averaged HRTF when worn. So to speak
headphones are equalized not to measure flat at your inner ear but to measure as a speaker
signal would approximately measure at the inner ear. This is of course a gross simplification.
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Some manufacturers prefer diffuse-field equalization, which assumes that the listening
environment includes sound-reflecting walls. Their frequency response graphs when
measured with an artificial head approximate those of a pair of loudspeakers in a reverbant
room, that is with equal sound power in almost all positions. Other manufactures use freefield equalization, which assumes that the listening environment is free of echoes so that only
the direct sound reaches the listener. Free-field equalized headphones can sound more direct,
vibrant and lively. Others don’t go by measurements at all and only trust their ears. There’s no
“correct” way of doing things. Sennheiser and Beyerdynamic use diffuse-field equalization
whereas Grado does not. Who is closer to the “truth”? That certainly is for the listener to
decide.
Source: http://www.headwize.com/images/diffuse.gif
Nevertheless, it has been found out in professional experiments that free-field equalization has
the tendency to produce a sound signature in headphones that sounds unnatural to most
listeners, i.e. differing from the original un-amplified acoustic event. Due to this, diffuse-field
equalized headphones were developed.
Personally, I would like to think that which headphone sounds the most natural to me, “wins”.
It’s of little practical use talking about the most natural-sounding headphone for everybody as
the diversity in headphone tastes only underlines this. There are many people who consider
Grado headphones more natural. There’s no consensus on what is the most natural sounding
headphone and wouldn’t it be somewhat fallacious to assume that other people like to choose
inaccurate and unnatural headphones?
Measuring FG
Highly expensive equipment is required for a relevant frequency measurement of headphones.
The problem with measuring headphones is that you can't measure the headphone's FR
outside the headphone-ear-head system whereas with speakers you can (measurement of freefield transducer in an anechoic chamber). That's also one of the main problems with
determining tonal accuracy or neutrality with headphones due to the lack of an objective
reference point. Further, as already mentioned, because of the close proximity between
headphones and the ear/head, there is more interference to worry about compared to speaker
measurements.
There are different approaches to measuring FR with headphones and to highlight the
difficulties involved: There’s not one definite way to measure FR with headphones that
everybody agrees with. For example, at which point does the measurement take place? Does
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the ear canal need to be blocked to avoid unwanted resonance with the ear canal? On the other
hand, the ear canal is not blocked during “real life performance” either. And this is only the
beginning.
Usually results below 200Hz mean little unless one is measuring in an anechoic chamber of
sufficient size and has proper equipment. Measurements above 8kHz are extremely tricky and
require the work of true experts using different measurement ears, measuring points,
techniques and statistical tools. If one takes into account, that most headphone measurements
are not done properly as outlined above, then it's no surprise that various headphone graphs
often disagree (esp. below 200Hz and above 8000Hz) and are suspect for any sort of serious
analysis.
How to read and use FG
The basic theory is rather straightforward: Lower Q resonance (spike/dent in the frequency
graph that is not great in deviation, but large in frequency band) is easier to hear as it crosses
several critical bands in hearing. Higher Q resonances (sharp spikes up/down) are not nearly
as easy to hear as they are to see. Q is the ratio of the center frequency divided by the
bandwidth.
It is important to notice, that this is in almost direct opposition to what people think is most
audible. Sharp narrow spikes are not as audible as we think and low & wide resonances are
much more audible than intuition might dictate.
Reality is that a FG is of very little use without having heard the headphone yourself. When
looking at FG of different headphones but by using the same measuring technique, you are
basically trying to examine differently equalized headphones (e.g. free-field, diffuse-field,
etc.) by using the same comparison method. Besides, closed headphones will measure
differently with an artificial head, depending on microphone position and ear type used.
Further, without knowledge on the exact measurement method or how the data might have
been weighted, there’s only little information to draw from FG. Comparing graphs from two
different experiments, especially from hobbyist but sometimes also professional sources, can
be even more misleading.
Even professionally measured FG often do not match with actual listening results done by
experts. Besides, headphones that measure very close to an idealized diffuse-field equalized
graph can sound like crap. To reiterate on this point: It is a known fact that measurements
often do not match listening results. Apparently the causes are not known and researchers are
still pondering over these issues. Please note that these are not merely headphone enthusiast
who like to spend their free time on headphone research but scientists with academic
experience on the subject. The people doing the listening tests are also those whose main
occupation is to find audible defects in sound (speech and music). That means these are true
experts in audio reproduction analysis and assessment - something, which for example
musicians rarely are, and which has been proven by studies.
Conclusion
It can be helpful for a deeper understanding, and for the fun of it, to check whether the FG
corresponds with actual listening results, whereas it can be misleading to check if a listening
result corresponds with a graph (and to assume that the graphs is necessarily correct). It is
especially dangerous to extrapolate FG results into how a headphone might sound. FG can at
times give clues as to what might be causing what one is hearing but often not more.
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Frequency response is only a small part of the story. How can you determine soundstage or
resolution with a FG? Besides, it is not possible to determine the tonal accuracy or the way a
certain headphone handles the timbres of various instruments from FG.
Frequency graphs can be very useful when you have an equlizer and you would like to trace
the roots of unwanted frequency flaws. The Sennheiser HD 25-1 for instance has a large spike
in the treble, which gives rise to its sibilant nature. A bit of experimentation with a precise
parametric equalizer can easily solve this issue and this where published frequency graphs
come in very handy. During this review I often played around with a parametric equalizer
while looking at frequency graphs published by Headroom in order to separate tonal from
technical characteristics of certain headphones.
To make a long story short, map is not terrain, graph is not sound. Trust your ears (or that of
others if you must), not some pretty graphs.
4.2 Reviews and Reviewers
As we have seen, frequency graphs are rather unreliable and should not be consulted when
trying to decide on a suitable headphone for oneself. However, since auditioning headphones
is not always feasible, one has to rely on the word and words of reviewers. In the following
chapter I’d like to show why reviewers’ opinions should be taken with a grain of salt as
well.40
The following remarks apply to reviews, reports and impressions in a more general sense. By
“reviewer” I mean every person who provides commentary on a certain piece of audio
equipment just as the term “review” will be used in a more general sense applying to formal
review as well as informal reports and impressions.
Psychological Influences
Since I am far from being knowledgeable on the topic of psychology, I can only point to the
more trivial explanations because I feel that even these simple aspects are often overlooked.
New-Toy-Syndrome
Most people have experienced the initial happiness of having received a new pair of shoes, a
new car or a new pair of headphones. It is highly understandable that unless the expectations
were truly disappointed, the new owner will go praising his or her new acquisition, be it in
order to justify his purchase to others or to himself (e.g. in order to overcome a prior buyer’s
remorse or simply to assure himself that it was the proper decision). The more expensive and
significant a purchase has been, the more one should be wary of this kind of behaviour.
Identification with one’s Headphone
Unlike the former case, the owner has now owned a particular headphone for a certain amount
of time. During this time several occasions have occurred in which he needed to defend his
headphone’s virtues. The problem is that the argument on things can easily shift to arguments
about persons and the credibility thereof. A long-term owner might consider an insult to his
headphone, amp or CD player as an insult to himself. He might consider his credibility or
40
I consider myself guilty as charged
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rationality being put into question. Or in case that he has managed to successfully promote a
certain piece of gear in the community, he might feel his influence threatened. Frankly, it’s
akin to an waitress feeling personally insulted by a negative comment on the food. Further,
people often forget that different people have different ears and different tastes. Being in
disagreement does not imply that somebody has a “bad” or even “wrong” taste because there
is no such thing.
Conformity
It is common knowledge that one prefers agreement than disagreement and hence tries to
avoid disagreement if possible - peer pressure. One way to do this is by saying the same
things that other people do. The Emperor’s New Clothes should be a familiar concept and the
point is that in the highly pluralistic headphone world, this approach has no reasonable
foundation at all. Conformity is a rather cheap form of consensus.
Happy and Wanting to Hear Differences
“You can’t hear it? Then you must have tin ears.” It is much harder to accept that there might
only be little or simply no difference at all than glorifying non-existent or miniscule
differences. Once you have managed to “hear” those differences, it’s for the others to follow
and one is always less likely to be criticized for non-obvious things. If the other party is not so
sure himself, he will be more inclined to simply take your word for it. On the other hand, it
will also cause him to desperately look for these apparently huge differences that is being
talked about but which might not have been there in the first place.
Placebo is all about “perceiving” things that are not there but which the person strongly
believes in (sometimes to the order of conviction). Being able to hear the differences will then
become a goal and happiness is achieved when this goal is reached.
While it is true that being able to appreciate and discern certain things in audio reproduction
(not music) come with time and experience, sometimes it still takes the courage and
innocence of a headphone “newbie” to admit that the emperor is not wearing any clothes at
all. However, since the audio emperor certainly is not bare-naked, one needs to have both a
good eye and decent understanding for fashion.
Psychoacoustical Influences
You can often hear people say: Different people hear differently. In this chapter we will see
how much truth this statement holds and how different listening volumes and others things
may affect our judgment of sound
Since perception of sound is psychological, it is called psychoacoustics. And unlike my
amateurish approach at explaining possible psychological effect, the following paragrahps on
psychoacoustics is backed up by scientific findings.
Volume
Human hearing is non-linear in that it is more sensitive to certain frequency regions than
others. Further, this non-linearity is loudness dependant and listening sensitivity changes with
sound pressure level (SPL).
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Source: http://www.aist.go.jp/aist_e/latest_research/2003/20031114/fig1.png
The Equal-Loudness Level Contour is a graph that shows the correlation between sound
pressure level (vertical axis), frequency (horizontal axis) and perceived equal loudness as
perceived by the average human ear (curves). As you can see from the graph, our hearing is
most sensitive to sounds in the midrange. At lower listening levels, the bass and treble may
sound subdued. Only at painstaking levels of about 120-130 dB do we even start to approach
linearity.
The increased sensitivity in the 2-4 KHz region (and another peak at about 13 KHz) is caused
by resonance effects with the auditory canal whose length stands in favorable proportionality
with the wavelength of sound in that frequency range. The increased sensitivity in the 2-4
KHz range is especially important for the understanding of speech.
This is an important issue because if different people listen to their music at greatly different
volume levels, then their listening results may vary as well. A person who listens at mostly
high volumes may complain about a lack of midrange whereas the quiet listener may find the
amount of midrange in relation to treble and bass to be just right.
Another issue is that the transducer itself may behave in a non-linear way. After passing
certain frequency regions, the non-linearities may account for the creation of harmonic
distortions, which will alter the sound in an unforeseeable fashion. Good equipment tries to
avoid that of course.
Different Ears / Different Hearing
A popular audiophile saying in the case of disagreements is that “different people have
different ears”. In fact, due to our ear varying shapes, we do perceive certain things
differently, especially in the treble region.
As we have already seen in chapter 4.1, the Head Related Transfer Function (HRTF) tells us
how the outer ears distort the sound signal naturally before it reaches the middle and inner ear
where the sound undergoes further alterations which are taken into account by the middle-ear
transfer function and inner-ear transfer function. Because people have different ear shapes,
these sound distortions vary from person to person and hence account for objectively different
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hearing. Think of HRTF as frequency-dependant intensity and time differences caused by the
pinna’s shape. HRTFs are also responsible for our three-dimensional localization of sound
sources and subject to a whole area of research.
Here is a graph of the HRTFs taken from three different persons measured at the left and right
ear using the same sound source.
Source: http://www.iem.at/
Note : Azimuth is the angle between ear and sound source on the horizontal plane
As you can see, sounds under the frequency range of 1-2 KHz are hardly affected by the
HRFT. In real life, these frequency regions can be affected by the person’s torso and head but
this is clearly a non-issue with headphone listening. Therefore to say that the variances in bass
are caused by personal differences in ears is exaggerating this effect. HRTFs are reasonably
steady at below 1 kHz, so person to person differences are much less likely to cause huge
impact differences at below 120 Hz. The reason people perceive bass differently is mostly due
to an improper seal, which depends on your ear/head shape, or positioning or the fact that
some people prefer their bass 'this' or 'that way'. Sometimes it can be difficult to deduce this
from the listening report.
Headphone listening is very subjective. In reality, it’s much more subjective than many
people would think it is - although not quite as subjective as some make it to be.
Baseline Principle
The baseline is the component to which the headphone in question is being compared to. This
is important because the human hearing works by comparing the current sound to a previously
heard sound, which has become the baseline of reference. If you play a totally flat noise (all
frequencies equal in amplitude) to a human for some time, it will be perceived as flat.
However, if you first play a simple tone at 200 Hz for the person and then play the same flat
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noise, the noise will be perceived as having a dip at 200 Hz. You will have to be exposed for
the noise for some time, until the dip disappears and the noise will be perceived as flat again.
Somebody who has been listening to a pair of Sennheiser HD 650 and switches to the AKG
K1000 will characterize the AKG as having a thin, overly bright and bass-less sound. Vice
versa, the Sennheiser will be described as dark and veiled.
This is basic psychoacoustics and cannot be circumvented, even if you know it's there. That's
just how our hearing works. It is therefore necessary to compare headphones both against and
independent from each other.
Also, because the sensitization to a signal happens over a time, it is important to keep
evaluating headphones over a longer period of time, with a varying set of baseline as a
comparison criteria.
If headphones are to be judged for their apparent naturality (how natural they sound) the
comparison must be against an unamplified, acoustic sound setting, preferably human
voice(s). Acoustic recordings will not do, it must be the real thing, not a replica. Even then,
the space (room, hall, field, etc) in which the acoustic event takes place can influence this
evaluation of naturality.
The baseline principle is one of the main reason why first impressions or meet impressions
need to be read with caution, especially if the to be tested equipment has vastly different
sound characteristics from the listener’s baseline components.
Personal Preferences
People have different preferences. This makes subjective assessment (listening and grading)
of headphones very difficult - unless one is a trained professional with a clear and honest
understanding of one's own preferences.
When one does not become aware of one's preferences and prejudices and especially baseline
of reference (the sound ideal to which everything new is compared to), then subjective
evaluation loses much of it's usefulness. It becomes useful only to the subject of doing the
comparison. Other people may not benefit a lot from that opinion.
Sensory evaluation is a relative evaluation (comparison against previous stimulus and most
common stimulus). It's not absolute points in a known scale (like measurements about sound
power are). There may even be national ideals or baselines. To Europeans it's often diffusefield equalized Sennheiser or Beyerdynamic headphones, which both have a different type of
house sound than American Grado or Japanese Sony.
When one listens to a new headphone from brand X and compares it to a different baseline,
there will be differences in opinions. This will be especially so when the listener is not aware
of this baseline preference. The least problematic baseline is the unamplified, acoustic
performance in the original setting. However, this is very hard to compare to, unless one does
his own recordings of music or human voices in an unamplified acoustics setting. Only
through this is it really possible to hone the expertise of a subjective evaluator, who is able to
say whether a piece of audio reproduction equipment is "natural", that is as close to the
original, unamplified performance as possible.
Again, if one's baseline is rock music mixed in a 16 track studio by a 45 year old engineer
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with an unknown set of monitoring speakers, it is very hard to compare this with the sound
you are trying to evaluate. What is the true sound of Neil Young's 'Harvest'? Very few people
know and it doesn't help a bit if Neil Young says his latest remastered CD is the way it should
have sounded the first time.
Personally, I favor “comparison by contrast” as outlined by Audio Note’s Road to Audio Hell
article. Due to the lack of a definite reference, “the more accurate system is the one which
reproduces more differences -- more contrast -- between the various programm sources.”
‘Programm sources’ here means different kinds of music because it’d be boring, frustrating
and most likely inaccurate if everything sounded the same.
In any event, neutrality and accuracy is an never-ending story in the audio world.
Other possible Influences
Biased Impartiality
This is probably the most common objection against reviews and impressions. I believe
reviewers will always let their bias shine through in spite of all the effort they may put into it.
Some reviewers take this as an incentive to skip objectivity as a whole but I don’t agree with
this approach either. In my opinion, an ideal approach would be to first identify a headphone’s
sound characteristics from an fairly objective point of view and then draw one’s personal
conclusion. However, the distinction that may sound simple in theory is hardly realizable in
practice. We have already seen that language, which is usually subjectively influenced by
connotations, plays an important role in the evaluation of equipment. Then there are other
issues such as different musical preferences. I have no doubt that most reviewers try to be
adequately objective but in all honesty, not even reviewers themselves believe in absolute
objectivity. Therefore it is important to have the reviewer’s personal preferences at hand.
Benevolent Attitude towards the Manufacturer
Most professional and amateur reviews will disclaim that their relationship to the
manufacturer has its influence on the review and in most cases this is also the case. However,
many professional writers are dependant on product samples and unless you write for a big or
influential audio magazine, where it is the manufacturer trying to get you to write a review for
them, a positive review will certainly propitiate the manufacturer to send further product
samples in the future. Even then, the magazine may depend on the manufacturer’s
advertisements.
The same applies to the amateur reviewer who, just as the professional reviewers, might be
thankful for new gear to review. A positive review surely is a good step towards that goal.
Further, he may have established a personal relationship to the manufacturer and hence feels
the urge to help out his “buddy”. In the worst case, it is the manufacturer who tries to push his
product by providing discounts or other gestures in exchange for a favorable review.
Nonetheless, I believe every reviewer should be given the benefit of doubt. Besides, it may be
highly possible that somebody simply likes a certain manufacturer’s sound signature or that a
certain manufacturer’s products are simply superior to everything else. The latter argument is
dubitable of course.
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Synergy and System Matching
One keyword in the world of audio is “synergy”. Grado headphones mate well with Melos
amps, the Sennheiser HD 650 and Headroom Blockhead make an excellent match, the AKG
K1000 and Audiovalve RKV MKII is a legendary pairing, and the list goes on. On the other
hand, sometimes the best of individual components simply don’t go together. These cases
must be individually tested in order to pass conclusive judgments. It is therefore both
necessary for the reader to be informed about the reviewer’s system as well as for the
reviewer to learn about synergy issues.
Language and Big Words
It’s difficult to put sounds into words to begin with and it is even more difficult to do so when
we don’t all hear the same. All the same, it is necessary to communicate listening results via
words, however they inaccurate they may be. One just needs to be aware of where the
problems can lie.
The basic problems are those of disparate conventions. When somebody claims that the
“treble” is fatiguing, what does he exactly mean? For some people the lower treble starts at
around 3 KHz while for others this still counts as upper midrange. Further when somebody
says that the midrange is lacking or feels sucked out, which part of the midrange is he
addressing? The midrange by generic definitions can go from 200 Hz up to 5 KHz.
Other linguistic problems require a more sophisticated analysis because certain words imply
connotations that can vary from user to user. For instance, what does ‘bright’ mean? For
some, it is merely an accentuation of a broader bandwidth mostly in the upper midrange or
lower treble, for others it can mean unwanted glare in the highs regardless of the frequency
response whereas for others it is an indication of discrete spikes in the treble region.
An audiophile’s favorite topic is the issue of ‘detailing’. Most audiophiles will tell you that
brightness does not equal detailing but can they really deny the fact that increased brightness
can lead to the perception of increased detailing? Others will then try to make the distinction
between detailing and resolution whereby the latter indicates natural detailing that integrates
itself into the musical flow with little effort. Instead of the details being shoved up you’re
your throat, higher resolution means that these details are simply more accessible to the
listener. Critics will argue that this is merely a semantic differentiation.
Another problem that can be observed rather often is that people tend to depict marginal
differences and discoveries as ostentatious debaucheries. Small variations in the sound will be
repainted to night and day differences.
A more amusing and perhaps self-evident issue is that reviewers often try to avoid negative
words. Instead of saying that the headphone lacks bass, they rather write that the bass could
have been better.
Music
How much is the rock lover’s opinion worth to the classical listener? Certain types of music at
times require different measuring criteria. Whereas the classical listener may put more
emphasis on a coherent sound, the drum and bass addict will focus more strongly on a deep
and impactful bass. Nevertheless, having the reviewer’s musical preferences at hand can be
misleading, too. Just because one rock lover prefers the aggressive nature of a Grado
headphone doesn’t mean that another rock lover might not prefer a less aggressive Sennheiser
sound since rock music is already aggressive to begin with. Still, it is a fact that certain types
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of music bring out certain aspects in the sound more than others and the review reader needs
to know what the reviewer’s musical preference are.
Amateur vs. Professional Reviews
Professional reviewers are often subject to editorial policies, pressure from manufacturers,
e.g. through advertisements, and are generally known to embellish what’s not there. The
downside to non-professional reviews is usually that they're written by amateurs on forums
and with amateurdom comes its own set of problem such as fanboyism, new toy syndrome,
peer pressure, buyer's remorse, lack of experience, lack of reference, lack of vocabulary, et al.
For me it usually comes down to choosing a comfortable compromise and an assorted mix of
information gathering.
Lack of Negative Reviews
The objection that reviewers never publish negative reviews is unsustainable because it bears
no rational foundation. Why should I bother and spend my precious time on unworthy
equipment? I’d much rather spend my time with quality gear. After all, audio is about passion
for good music and dedication for good musical reproduction.
What I'm sometimes missing is not the negative review but rather the more explicitly stated
negative paragrahps in the review about a certain piece of equipment. Usually, there are bit
and pieces of information on where the drawbacks might be found but some
reviews/reviewers don't even bother and most don't bother enough in my opinion.
Conclusion
As I said in the introduction, the words of reviewers and commentaries in general need to be
taken with a grain of salt. You may also understand see why I don’t consider personal
headphone rankings to be overly helpful unless I am familiar with the specific person’s tastes.
Surely, if ten people agree that a certain headphone is the best, then there might some truth to
it, but fact is that no ten people will ever agree on that.
In the worst case, you have a narrow-minded fan-boy, whose opinions are worth no more than
that of a deaf man (at least he is impartial) or my favorite kind of person who criticizes
headphones, amps, etc. without actually having heard them, i.e. a deaf man with the hubris of
not needing to be impartial. Recommending unheard audio equipment in general, however, is
a tricky issue. On the one hand, it can be useful if somebody is looking for data and you have
that data albeit not first-hand whereas on the other hand, it can easily develop into a snowball
effect. Personally, I would still add a few comments on unheard gear in order to provide the
inquirer with a bigger variety on his shortlist.
Summing up, I would also like to add a personal experience of mine. A few months ago I did
some research on portable amps and even though I though I was able to imagine the sound
signature of the Emmeline SR-71 amp very well from reading review and impressions, and
which surprisingly turned out to be accurate, too, I was rather surprised that I did in fact liked
the way it was sounded in the end. This may sound a bit strange but my point is that even if
somebody was perfectly able to imagine the sound of a certain headphone or amp, there is no
guarantee on how good it will sound or what kind of emotional reaction it will evoke without
first-hand experience. Certainly, this kind of accuracy improves as the overall exposure to
audio increases.
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I always thought that reading reviews and impressions is somewhat similar to reading the
sheet music of a certain piece. Even if you know all the notes by heart, you don't really know
the piece. Certainly, you can somewhat visualize the eventual outcome based on the piece's
notes, but how do you know if a particular piece might not be better off ending with a major 7
chord instead of a major 6?
4.3 Conclusion
So, finally it all boils down to what one likes. And this is what should matter to 99% of us,
right? It's not the pretty graphs, not whether somebody else likes it or if it has universal
approval as "one of the best in it's class". Those are all just methods to make us feel
comfortable and secure about our choices.
Is this a pleading against posting reviews and discussing headphones? Certainly not. And as I
said in the introduction, reviews should be seen as incentives, not decision-makers - in an
ideal world. If possible, try to consult online shops with flexible return policies, frequent local
electronics stores, ask people for a lending or attend a headphone meet. If that all is not
possible and that is very often the case, I think reading a review, impressions or posting on
audio forums can be very beneficial. Especially fruitful discussions can be among the most
useful things to determine the right audio gear as specific issues can be scrutinized and
verified.
I think reading between the lines of audio reviews is in fact an acquired skill and it is often
necessary to read reviews and impressions with certain reservations. If there’s one thing I’ve
been trying to convey here, it is not that these reservations should keep you from reading or
trusting reviews, but that there are simply quite a many things to keep in mind when doing so.
As for the remaining 1%, they continue on their journey trying to train their ear and eye by
listening, recording, reading, testing, discussing all at the same time while trying to keep in
mind that it's the enjoyment that matters and that graphs or reviews should not be used as
beating sticks against listeners or makers of certain headphones. If it sounds good, it is good.
5. Appendix
Further Reading
Recommended readings for further interest. Compiled with help from Head-Fi member
Halcyon.
Headphone related
Everything you ever wanted to know about Headphones. Extensive library.
http://headwize.com/library.htm
Tips and simple modifications for any closed headphones:
http://www.meier-audio.homepage.t-online.de/tipstricks.htm
Understanding Headphone Power Requirements
http://www.rane.com/note100.html
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Hearing related
Headphone Listening Test Methods
http://www.acoustics.hut.fi/publications/files/theses/hirvonen_mst.pdf
Sound Quality
http://www.acoustics.hut.fi/teaching/S-89.320/2005/KA10.pdf
Fundamentals of psychoacoustics
http://www.faqs.org/docs/sp/sp-171.html
Fundamentals of Psychoacoustics
http://www.acoustics.hut.fi/teaching/S-89.320/2005/KA6a.pdf
http://www.acoustics.hut.fi/teaching/S-89.320/2005/KA6b.pdf
Other psychoacoustic concepts
http://www.acoustics.hut.fi/teaching/S-89.320/2005/KA7.pdf
Psychoacoustics and Music
http://cara.gsu.edu/courses/MI_3110/psycho.html
Acoustics listening demos
http://theory.esm.rochester.edu/th412/listening/listening.html
Hearing - structure and function
http://www.acoustics.hut.fi/teaching/S-89.320/2005/KA5.pdf
Sound and Hearing
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html
Research papers on psychoacoustics, some are in English
http://iem.at/projekte/publications/iem_report/
Auditory Localization in the Near-Field
http://www.icad.org/websiteV2.0/Conferences/ICAD96/proc96/brungart.htm
HRTF measurements of a Kemar Dummyhead
http://sound.media.mit.edu/KEMAR.html
Books
An Introduction to the Psychology of Hearing, Brian C.J. Moore, 5th edition, 2003
Auditory Perception, Richard M. Warren, Cambridge University Press, 1999
The Intelligent Ear, Reinier Plomp, Lawrence Erlbaum Associates, 2002
Psychoacoustics: Facts and Models, Eberhard Zwicker/Hugo Fastl
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Misc
Road to Audio Hell (The concept of ‘comparison by contrast’ instead of ‘comparison by
reference’)
http://www.enjoythemusic.com/audiohell.htm
Extensive library on Audio Electronics with basic explanations of Signal Processing, A/D, ...
http://www.rane.com/library.html
Dictionary for technically versed audio terminologies (e.g. ‘clipping’, ‘balanced amplifier’,
etc.)
http://www.rane.com/digi-dic.html
Why Equalizers are not evil
http://www.enjoythemusic.com/magazine/equipment/0101/behringer8024.htm
Author: Tao Tao
Date: 8/5/2005
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