FAILURE ANALYSIS
LISTING OF INITIAL CAUSES
- Applicable to all loudspeaker and compression driver types
- Applicable to the analysis of power handling capacity results
Update: 14/02/2007
DEFECT
CODE
BA
BB
BC
BD
BF
BG
BK
BL
BM
BR
BS
BT
BZ
CB
CR
CS
DC
DG
Bad Assembly
Broken
Basket
Broken
Cone
Broken
Dust-cap
Blistered
Former
Broken
Diaphragm
Buckling
Former
Broken
loudspeaker or
compression driver
Broken
Magnet
Bad
Reconing
Bad
Diaphragm
Replacement
Broken
Terminals
Buzzing
Cut
Braids
Coil Rubbing
Cold
Solder
Direct
Current
Detached
Grille
LISTING OF INITIAL
CAUSES
WARRANTY
STATUS
Defective product assembly. Factory
specifications not fulfilled
Broken or warped basket due to shock or
mechanical strain
Folded or torn cone due to tear and wear
or bad handling
IN
OUT
Sagging or perforated Dust-cap
OUT
Blistering of the former facing the
winding
Broken or warped diaphragm due to
excessive power or bad handling
Buckling of the voice-coil former
( Voice-coil driven out of the air-gap)
IN
OUT
Complete destruction of the loudspeaker
OUT
Splitt ring magnet. The voice-coil is
jammed in the air-gap
IN
Bad reconed unit
OUT
Bad user-replaced diaphragm
OUT
Broken electrical terminals due to shock
or bad handling
Unusual noise in sinusoidal excitation
(Buzz)
Lead-out braid cut by mechanical fatigue
breaking
The voice-coil rubs the gap’s surface
producing extraneous noise
OUT
Cold solder of the lead-out braids
IN
Carbonisation of one half of the coil
OUT
Venting hole grille detached or lost
IN
REMARKS
OUT
OUT
No possibility of service
IN
Specify applied voltage and
frequency
IN
See also 'TB' code
IN
Voice-coil in open circuit
DEFECT
CODE
DK
DR
DS
EW
FA
FR
IR
LB
LD
LP
LS
MA
ML
MM
MS
OC
Detached
Gasket
Detached
Double Spider
Detached
Surround
LISTING OF INITIAL
CAUSES
WARRANTY
STATUS
Loudspeaker gasket detached
IN
Glue joint failure between spiders
IN
Unsticking or delamination of surround
from the cone
IN
Expired
Warranty
Three year warranty expired
OUT
Filings in air-gap
Filings in the air-gap
IN
Bad Frequency
Response
Bad Impedance
Response
Frequency response curve goes outside
the accepted QC limits
Impedance response curve goes outside
the accepted QC limits
Too long braids hit the cone during
operation
IN
Dust-cap loose from cone
IN
Compression driver phase plug loose
IN
Too Long Braids
Loose
Dust-cap
Loose
Phase Plug
Broken or Lost
Screws
Missing Article
Missing
Label
Missing
Moving Parts
Melted
Solder
Open
Circuit
Loudspeaker or compression driver
assembly screws completely or partially
broken or lost
Article listed in the delivery note not
present in the shipped items
Missing loudspeaker or compression
driver label
IN
OUT
OUT
OUT
Missing moving parts
OUT
Melting of the aluminum winding solders
IN
IN
OUT
OD
Over
Driven
OH
OK
OP
OS
OV
RP
SB
SC
SG
SN
Over
Heated
O.K.
No Defect Found
OUT
Out of Production
Discontinued Product
OUT
Out of Specifications
IN
Ovalized Voice-coil causes Rub
IN
Metal Parts Oxidation
IN
Too short lead-out braid, cut during
operation
Winding in short-circuit by melting with
the return wire
Breaking of the spider / voice-coil or
spider/ frame gluing joint
Unusual noise coming from cone
suspension in sinusoidal excitation (Buzz)
IN
Rusty Plate
Too Short Braids
Short-Circuit
Spider
Glueing
Side Noise
Production year and week is
coded on batch number
printed on label
IN
Winding in open-circuit by breaking of
output wire at fatigue
Exceeding of excursion limits: circularly
folded cone and/or bottomed voice-coil.
Damaged suspension and/or sign of phase
plug on diaphragm in compression
drivers
Overheating of the voice-coil. The coil is
carbonized
Out of
Specifications
Ovalized
Voice-coil
REMARKS
OUT
IN
IN
IN
Specify applied voltage and
frequency
DEFECT
CODE
SP
SS
SW
TB
TS
TU
VG
WI
LISTING OF INITIAL
CAUSES
WARRANTY
STATUS
Shifted
Plate
Softened
Spider
Slipped
Winding
Teared
Braids
Front or rear plate shifted. The voice-coil
is jammed in the air-gap
IN
Softened spider causes Rub or Buzz
IN
Partial or complete shifting of coil
winding
IN
Lead-out braid accidentally snatched
OUT
Torn Spider
Torn or broken spider
IN
Out-of-shape or torn surround
IN
Breaking of the voice-coil to cone or
diaphragm gluing joint
Winding in open-circuit by melting with
the return wire
IN
Torn
Surround
Voice-coil
Glueing
Winding
Insulation
IN
REMARKS