Mono and Stereo
Miking Techniques
Choosing Microphones
Limited collection: useful for broad range
of applications
Neumannn KM 184’s (desert island mic’s)
Small collection
Small diaphragm stereo pair of cardiod condensers
(184’s)
Large diaphragm condenser (U87, KSM 44, AT
4050).
Standard dynamics (SM 57/58, Sennheiser 421)
Pair of omni’s, if not included above (higher costs)
Multiple polar patterns a real plus on a budget
Choosing Microphones (2)
Large collection of mic’s perceived to have
specific individual applications.
Higher-end ribbon microphones
Tube condensers
Different types of vocal microphones
“Boutique” and Vintage microphones: Blue
series, AKG C414, C12, U67
Microphone Placement / Working
Distance
Distant
Close
(Accent)
Ambient
Distant Mic Placement
 “3 ft or more” away from source. (often further)
 Captures direct and reflected sound
 Pro’s
Useful for picking up an ensemble
Natural tonal balance (at distance roughly equal to size
of sound source)
Capture’s room acoustics naturally.
 Con’s
Room acoustics must be good
Phase cancellation can be a problem
Close Microphone Placement


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1 inch to 3 feet
“present” sound quality
Excludes acoustic environment (isolation)
Tonal balance can be a problem
 Instruments don’t radiate all frequencies in all directions
 Leakage should be avoided
 Physical distance between sources
 Directional microphones
 Gobo (acoustic barrier)
 3:1 distance rule: Nearby mic’s should be three times the
distance from a particular mic as that particular mic is
from its sound source.
Ambient Microphone Placement
Large distance from source - reverberant
signal more prominent than direct.
Control over natural reverb level in stereo
or surround applications
Audience reaction
Natural room acoustics
Stereo Miking Techniques
 The use of two (or more) microphones to obtain a
coherent stereo image.
 Coincident; Near Coincident; Spaced
 Coincident yields excellent stereo image (individual
placement of sound sources).
 Spaced yields a more spacious-sounding result.
 Near Coincident techniques attempt a compromise.
 Five main techniques:
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
Spaced Pair
X/Y
ORTF
M/S
Decca tree
Spaced Pair
Two mic’s (same make and model), placed
in front of an instrument/ensemble.
Spacing ranges from a couple of feet to
over 30 feet.
Typically, omni pickup pattern is used.
Interaural time and interaural amplitude
cues create stereo image.
Potential for phase problems, especially
when mixed to mono.
X/Y
 Two directional microphones (same make and
model) placed as close together as possible
without touching. (coincident technique)
 Generally at angle of 90° to 135°.
 Midpoint faces towards middle of source.
 Directionally comes entirely from amplitude
differences.
 No phase problems.
 Cardiod or bi-directional
 Bidirectional gives the “Blumlein” pattern, which
can yield excellent ambient results.
ORTF
 Near coincident technique.
 Two directional microphones (same…),
symmetrically angled outwards at 110°, about 17
cm apart.
 simulates physical ear placement
 Combines directional amplitude differences and
interaural arrival time differences.
 Best when used at a distance from ensemble.
 Named after French National Broadcasting
Organization. (Office of Radiodiffusion—
Television Française)
M/S
 Mid-side technique, using a cardiod pattern pointed at the sound
source, and a bi-directional microphone oriented towards the sides
(90° and 270°)
 The mid pickup captures the source, while the side pickup captures
ambience.
 Offers excellent control of source-to-ambient balance, even after
recording.
 Excellent source pickup for chamber music.
 No phase problems when mixed to mono. (coincident)
 Requires a decoder/transformer matrix:
 Software decoder, or
 The side pickup is sent to two channels, with the phase reversed on
one channel.
M+S=X; M-S=Y
Decca Tree
 A near-coincident technique, developed for
stereo recordings of orchestras.
 Typically, two microphones spaced about 1
meter apart. Center microphone about 0.5 meter
in front of other microphones.
 Omni pickups typically used, but variations
possible. (Neumann M50’s is the classic choice.)
 Outer mic’s panned hard L and R; Center
microphone panned center, but with lower level.
 Tree placed above and behind the conductor of
an orchestra.