JBL PowerBass PB12 User manual

PowerBassSeries
PB12 Subwoofer
PRELIMINARY
SERVICE MANUAL
JBL Incorporated, Inc.
250 Crossways Park Dr.
Woodbury, New York 11797

- CONTENTS -
BASIC SPECIFICATIONS ……….……………….…….……………..……………..2
DETAILED PB12 SPECIFICATIONS…………………….……….……..……………....3
CONNECTIONS…………………………………………………..……………..………..4
OPERATION………………………………….……………………………………..…….8
TROUBLESHOOTING…………………….…………….………………..….……..…….9
ELECTRICAL PARTS LIST ……………….…………..…………..……………….…10
MECHANICAL/PACKING PARTS LIST……………….……..……….…………….…15
PCB DRAWINGS……………….…………..……………….………..….………………16
SCHEMATICS ………..……………………..………………...…….………………..19
1

GENERAL SPECIFICATIONS PB12 Subwoofer
Output Power 250 watts RMS
Driver 12" Woofer
Frequency Response 25Hz – to Low Pass Frequency setting
Inputs Line Level (option: LFE); Speaker Level
Outputs Speaker level fixed frequency 150Hz
Low-Pass Frequency Variable from 50Hz – 150Hz
High-Pass Frequency 150Hz when using Speaker Level Output
Dimensions (H x W x D) 15 1/2" x 15" x 16"
394mm x 381mm x 406mm
(with feet) 17 1/2" x 15" x 16"
445mm x 381mm x 406mm
Weight 40 lb/18.2kg
Refinements may be made on occasion to existing products without notice but will always meet or exceed original
specifications unless otherwise stated.
PowerBass is a registered trademark of JBL Incorporated. 2

JBL PB 12 250W Powered Sub Amp
LINE VOLTAGE Yes/No Hi/Lo Line Nom. Unit Notes
US 120vac/60Hz Yes 108-132 120 Vrms Normal Operation
EU 230vac/50-60Hz Yes 207-264 230 Vrms Normal operation, MOMS required
Parameter Specification Unit QA Test Limits Conditions Notes
Amp Section
Type (Class AB, D, other) Dn/a n/a
Load Impedance (speaker) 5.6 Ohms n/a Nominal
Rated Output Power 250 Watts 145 1 input driven Peak
THD @ Rated Power 0.3 %122k filter 145 Watts
THD @ 1 Watt 0.1 %0.5 22k filter
DC Offset 10 mV-DC 20 @ Speaker Outputs
Damping factor >50 DF 35 Measured at amplifier board Measured at the speaker cable. 150 Watts @
THD < 0.1 % @ 50 Hz
Input Sensitivity
Input Frequency 50 Hz 50 Nominal Freq.
L&R 240 mVrms ±2dB To 150 Watts Single input driven
LFE input 240 mVrms ±2dB To 150 Watts Single input driven, LFE switch ON
Speaker/Hi Level Input 2.4 Vrms ±2dB To 150 Watts Single input driven
Signal to Noise
SNR-A-Weighted 90 dBA 80 relative to rated power A-Weighting filter
SNR-unweighted 85 dBr 80 relative to rated power 22k filter
SNR rel. 1W-unweighted 65 dBr 60 relative to 1W Output 22k filter
Residual Noise Floor 1mVrms 2Volume @max, using RMS reading
DMM/VOM (or A/P) BW=20 Khz.
Residual Noise Floor 1.5
mVrms(max)
2
Volume @max, w/ A/P Swept
Bandpass Measurement (Line
freq.+ harmonics) (BW=20 Khz)
Input Impedance
Line Input (L, R,LFE) 20K ohms n/a Nominal
Speaker/Hi Level Input 4.7K ohms n/a Nominal
Filters
LP filter 4th order fixed 60-180 Hz ± 10 2nd order variable + 2nd order fix-24 db/Octave
Subsonic filter (HPF) 2nd Order
Fixed
LFE Low pass 2nd order 200>LP<1K Hz LFE input driven only
HP speaker out connector 200 Hz ± 10 Speaker input driven - 4 Ohms
100 Hz ± 10 Speaker input driven - 8 Ohms
Limiter
THD at Max. Output Power n/a n/a functional Maximum Output Power Maximum THD as a result of limiting.
Features --
Volume pot Taper (lin/log) LOG -- functional A Taper
HP Speaker out YES functional Refer to Filter section
Phase switch 0-180 deg functional
LP Filter defeat switch YES functional Disables LP filter, intended for LFE
Input Configuration
Line In (L,R) & LFE YES -- functional Dual RCA jack
Spkr/Hi Level In YES -- functional Binding post connector L&R
Signal Sensing (ATO)
Auto-Turn-On (yes/no) YES functional
ATO Input test frequency 50 Hz functional "
ATO Level LFE Input 4mV functional "Maximum acceptable level.
ATO Level Speaker in 50 mV functional "Maximum acceptable level.
ATO Turn-on time 5ms functional Amp connected and AC on, then
input signal applied
Auto Mute/ Turn-OFF Time 15 minutes 15 T before muting, after signal
removed
Auto turn of time (T) must be 5 > T < 15
Minutes
Power on Delay time 3sec. 4AC Power Applied
Transients/Pops
ATO Transient 5mV-peak n/a @ Speaker Outputs
Turn-on Transient 50 mV-peak 2v-pp @ Speaker Outputs AC Line cycled from OFF to ON
Turn-off Transient 50 mV-peak 2v-pp @ Speaker Outputs AC Line cycled from ON to OFF
Efficiency
Efficiency 65 %64 Nominal Line voltage 120 VAC
Stand-by Input Power 24 Watts 26 @ nom. line voltage
Power Cons. @ rated power 234 Watts 240 @ nom. line voltage 150 Watts @ 5.6 Ohms nominal line voltage
Short Circuit Protection YES functional Direct short at output Amplifier should resume operation after short
Thermal Protection YES functional
DC Offset Protection YES -DC present at Speaker Out leads
Line Fuse Rating
USA-Domestic (120v) 2Amps Type-T or Slo Blo-250 V
EU (230v) 1Amps Type-T or Slo Blo-250 V External fuse with UL/SEMKO rated holder

2
1. Read Instructions. All the safety and
operating instructions should be read before
the product is operated.
2. Retain Instructions. The safety and
operating instructions should be retained
for future reference.
3. Heed Warnings. All warnings on the
product and in the operating instructions
should be adhered to.
4. Follow Instructions. All operating and use
instructions should be followed.
5. Cleaning. Unplug this product from the
wall outlet before cleaning. Do not use
liquid cleaners or aerosol cleaners. Use a
damp cloth for cleaning.
6. Attachments. Do not use attachments not
recommended by the product manufacturer,
as they may cause hazards.
7. Water and Moisture. Donot use this
product near water – for example, near a
bathtub, wash bowl, kitchen sink or laundry
tub; in a wet basement; or near a swimming
pool; and the like.
8. Accessories. Do not place this product on
an unstable cart, stand, tripod, bracket, or
table. The product may fall, causing serious
injury to a child or adult, and serious
damage to the product. Use only with a cart,
stand, tripod, bracket, or table recommended
by the manufacturer, or sold with the
product. Any mounting of the product should
follow the manufacturer’s instructions, and
should use a mounting accessory
recommended by the manufacturer.
9. A Product and Cart Combination Should
Be Moved with Care. Quick stops, excessive
force, and uneven surfaces may cause the
product and cart combination to overturn.
10. Ventilation. Slots and openings in the
cabinet are provided for ventilation and to
ensure reliable operation of the product and
to protect it from overheating, and these
openings must not be blocked or covered.
The openings should never be blocked by
placing the product on a bed, sofa, rug, or
other similar surface. This product should
not be placed in a built-in installation such
as a bookcase or rack unless proper
ventilation is provided or the manufacturer’s
instructions have been adhered to.
11. Power Sources. This product should be
operated only from the type of power source
indicated on the marking label. If you are
not sure of the type of power supply to your
home, consult your product dealer or local
power company. For products intended to
operate from battery power, or other
sources, refer to the operating instructions.
12. Grounding or Polarization. This product
may be equipped with a polarized alter-
nating-current line plug (a plug having one
blade wider than the other). This plug will fit
into the power outlet only one way. This is a
safety feature. If you are unable to insert the
plug fully into the outlet, try reversing the
plug. If the plug should still fail to fit, contact
your electrician to replace your obsolete
outlet. Do not defeat the safety purpose of
the polarized plug.
13. Power-Cord Protection. Power-supply
cords should be routed so that they are not
likely to be walked on or pinched by items
placed upon or against them, paying
particular attention to cords at plugs,
convenience receptacles, and the point
where they exit from the product.
14. Nonuse Periods. The power cord of the
product should be unplugged from the outlet
when left unused for long periods of time.
15. Outdoor Antenna Grounding. If an outside
antenna or cable system is connected to the
product, be sure the antenna or cable
system is grounded so as to provide some
protection against voltage surges and built-
up static charges. Article 810 of the National
Electrical Code, ANSI/NFPA 70, provides
information with regard to proper grounding
of the mast and supporting structure,
grounding of the lead-in wire to an antenna
discharge unit, size of grounding conductors ,
location of antenna-discharge unit,
connection to grounding electrodes, and
requirements for the grounding electrode.
See Figure A.
16. Lightning. For added protection for this
product during a lightning storm, or when
it is left unattended and unused for long
periods of time, unplug it from the wall outlet
and disconnect the antenna or cable system.
This will prevent damage to the product due
to lightning and power-line surges.
17. Power Lines. An outside antenna system
should not be located in the vicinity of
overhead power lines or other electric light
or power circuits, or where it can fall into
such power lines or circuits. When installing
an outside antenna system, extreme care
should be taken to keep from touching such
power lines or circuits, as contact with them
might be fatal.
18. Overloading. Do not overload wall
outlets, extension cords, or integral
convenience receptacles, as this can
result in a risk of fire or electric shock.
19. Object and Liquid Entry. Never push
objects of any kind into this product through
openings, as they may touch dangerous
voltage points or short-out parts that could
result in a fire or electric shock. Never spill
liquid of any kind on the product.
20. Servicing. Do not attempt to service this
product yourself, as opening or removing
covers may expose you to dangerous
voltage or other hazards. Refer all servicing
to qualified service personnel.
21. Damage Requiring Service. Unplug this
product from the wall outlet and refer ser-
vicing to qualified service personnel under
the following conditions:
a. The power-supply cord or the plug has
been damaged; or
b. Objects have fallen onto, or liquid has
been spilled into, the product; or
c. The product has been exposed to rain or
water; or
d. The product does not operate normally
when following the operating instructions.
Adjust only those controls that are covered
by the operating instructions, as an improper
adjustment of other controls may result in
damage and will often require extensive
work by a qualified technician to restore the
product to its normal operation; or
e. The product has been dropped or
damaged in any way; or
f. The product exhibits a distinct change
in performance – this indicates a need for
service.
22. Replacement Parts. When replacement
parts are required, be sure the service
technician has used replacement parts
specified by the manufacturer or that have
the same characteristics as the original part.
Unauthorized substitutions may result in fire,
electric shock or other hazards.
23. Safety Check. Upon completion of any
service or repairs to this product, ask the
service technician to perform safety checks
to determine that the product is in proper
operating condition.
24. Wall or Ceiling Mounting. The product
should be mounted to a wall or ceiling only
as recommended by the manufacturer.
25. Heat. The product should be situated
away from heat sources such as radiators,
heat registers, stoves, or other products
(including amplifiers) that produce heat.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: To prevent electric shock,
do not remove the grounding plug
on the power cord, or use any plug
or extension cord that does not have
a grounding plug provided.
Make certain that the
AC outlet is properly grounded.
Do not use an adapter plug
with this product.
The lightning flash with arrowhead symbol,
within an equilateral triangle, is intended to
alert the user to the presence of uninsulated
“dangerous voltage” within the product’s
enclosure that may be of sufficient magnitude to constitute a
risk of electric shock to persons.
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and
maintenance (servicing) instructions in the
literature accompanying the appliance.
Antenna Lead-In Wire

Ground Clamp

Antenna Discharge Unit (NEC Section 810-20)

Grounding Conductors (NEC Section 810-21)

Electric Service Equipment

Ground Clamps

Power Service Grounding Electrode System
(NEC Art 250, Part H)
Figure A.
Example of Antenna
Grounding as per National
ElectricalCode, ANSI/NFPA 70
READ THIS! Important Safety Precautions! SPEAKER PLACEMENT
Part No. JBLULB 10/99
• As a general rule, bass
response increases as a
subwoofer is placed closer
to a wall. Therefore, bass
output is maximized when
the subwoofer is placed in
a corner.
• It is also recommended that
the subwoofer be
positioned along the
same wall as the front
loudspeakers.
Low-frequency sounds are
normally omnidirectional,
meaning the listener can’t tell
where they are generated
from. However, frequencies
between 75Hz – 150Hz can be
localized, especially at higher
volume levels. Positioning
your subwoofer as recom-
mended will provide the
most natural soundstage
and imaging from your
loudspeaker system.
Remember that these are just
guidelines. Since every
listening room is different,
JBL strongly recommends
experimenting with the
positioning of your subwoofer
to obtain the most pleasing
results in your room. One
technique that can help you
find the ideal subwoofer
location is to temporarily
place the subwoofer near the
main listening location. Then
move around the room and
determine where you hear
the most pleasing bass
performance. This would then
be the ideal location for the
subwoofer.
When we designed the
PB10 and PB12 powered
subwoofers, our goal was
to offer the user the best
possible performance
combined with the most
flexible and complete
installation options. Please
look over the following three
examples to determine which
description best matches your
system and follow the
corresponding hookup
instructions.
To use the binding-post
speaker terminals with bare
wire, unscrew the collar until
the hole through the center
post is visible under the collar.
Insert the bare end of the wire
through the hole in the post,
then screw the collar back
down until the connection is
tight. The holes in the center
of the collars are intended for
banana-type connectors.
Dolby* Pro Logic* (Non-Digital) – Speaker Level
Use this installation method
for Dolby Pro Logic appli-
cations (not Dolby Digital,
DTS®or other digital
processing), where the
receiver/processor does not
have a subwoofer output or
a volume-controlled preamp
(line-) level output:
Connect your receiver or
amplifier’s front left and right
speaker terminals to the left
and right terminals on the
subwoofer that are marked
“High Level In.” Connect the
left and right terminals on the
subwoofer that are marked
“High Level Out” to the cor-
responding terminals on the
back of your front left and
right speakers.
Connect your receiver or
amplifier’s center, left and
right surround-speaker
terminals to the corre-
sponding terminals on the
back of your center, left and
right surround speakers.
SPEAKER CONNECTION
Right Front
Left Front Center + –
+ – + –
Subwoofer
Right SurroundLeft Surround
+ – + –
+ –
+ –
Left Front Center
+ –
Left Surround
Right Front
+ –
Right Surround
+ –
Receiver
L
R
HIGH
LEVEL
IN
L
R
L
R
HIGH
LEVEL
OUT`
+ –

2
1. Read Instructions. All the safety and
operating instructions should be read before
the product is operated.
2. Retain Instructions. The safety and
operating instructions should be retained
for future reference.
3. Heed Warnings. All warnings on the
product and in the operating instructions
should be adhered to.
4. Follow Instructions. All operating and use
instructions should be followed.
5. Cleaning. Unplug this product from the
wall outlet before cleaning. Do not use
liquid cleaners or aerosol cleaners. Use a
damp cloth for cleaning.
6. Attachments. Do not use attachments not
recommended by the product manufacturer,
as they may cause hazards.
7. Water and Moisture. Donot use this
product near water – for example, near a
bathtub, wash bowl, kitchen sink or laundry
tub; in a wet basement; or near a swimming
pool; and the like.
8. Accessories. Do not place this product on
an unstable cart, stand, tripod, bracket, or
table. The product may fall, causing serious
injury to a child or adult, and serious
damage to the product. Use only with a cart,
stand, tripod, bracket, or table recommended
by the manufacturer, or sold with the
product. Any mounting of the product should
follow the manufacturer’s instructions, and
should use a mounting accessory
recommended by the manufacturer.
9. A Product and Cart Combination Should
Be Moved with Care. Quick stops, excessive
force, and uneven surfaces may cause the
product and cart combination to overturn.
10. Ventilation. Slots and openings in the
cabinet are provided for ventilation and to
ensure reliable operation of the product and
to protect it from overheating, and these
openings must not be blocked or covered.
The openings should never be blocked by
placing the product on a bed, sofa, rug, or
other similar surface. This product should
not be placed in a built-in installation such
as a bookcase or rack unless proper
ventilation is provided or the manufacturer’s
instructions have been adhered to.
11. Power Sources. This product should be
operated only from the type of power source
indicated on the marking label. If you are
not sure of the type of power supply to your
home, consult your product dealer or local
power company. For products intended to
operate from battery power, or other
sources, refer to the operating instructions.
12. Grounding or Polarization. This product
may be equipped with a polarized alter-
nating-current line plug (a plug having one
blade wider than the other). This plug will fit
into the power outlet only one way. This is a
safety feature. If you are unable to insert the
plug fully into the outlet, try reversing the
plug. If the plug should still fail to fit, contact
your electrician to replace your obsolete
outlet. Do not defeat the safety purpose of
the polarized plug.
13. Power-Cord Protection. Power-supply
cords should be routed so that they are not
likely to be walked on or pinched by items
placed upon or against them, paying
particular attention to cords at plugs,
convenience receptacles, and the point
where they exit from the product.
14. Nonuse Periods. The power cord of the
product should be unplugged from the outlet
when left unused for long periods of time.
15. Outdoor Antenna Grounding. If an outside
antenna or cable system is connected to the
product, be sure the antenna or cable
system is grounded so as to provide some
protection against voltage surges and built-
up static charges. Article 810 of the National
Electrical Code, ANSI/NFPA 70, provides
information with regard to proper grounding
of the mast and supporting structure,
grounding of the lead-in wire to an antenna
discharge unit, size of grounding conductors ,
location of antenna-discharge unit,
connection to grounding electrodes, and
requirements for the grounding electrode.
See Figure A.
16. Lightning. For added protection for this
product during a lightning storm, or when
it is left unattended and unused for long
periods of time, unplug it from the wall outlet
and disconnect the antenna or cable system.
This will prevent damage to the product due
to lightning and power-line surges.
17. Power Lines. An outside antenna system
should not be located in the vicinity of
overhead power lines or other electric light
or power circuits, or where it can fall into
such power lines or circuits. When installing
an outside antenna system, extreme care
should be taken to keep from touching such
power lines or circuits, as contact with them
might be fatal.
18. Overloading. Do not overload wall
outlets, extension cords, or integral
convenience receptacles, as this can
result in a risk of fire or electric shock.
19. Object and Liquid Entry. Never push
objects of any kind into this product through
openings, as they may touch dangerous
voltage points or short-out parts that could
result in a fire or electric shock. Never spill
liquid of any kind on the product.
20. Servicing. Do not attempt to service this
product yourself, as opening or removing
covers may expose you to dangerous
voltage or other hazards. Refer all servicing
to qualified service personnel.
21. Damage Requiring Service. Unplug this
product from the wall outlet and refer ser-
vicing to qualified service personnel under
the following conditions:
a. The power-supply cord or the plug has
been damaged; or
b. Objects have fallen onto, or liquid has
been spilled into, the product; or
c. The product has been exposed to rain or
water; or
d. The product does not operate normally
when following the operating instructions.
Adjust only those controls that are covered
by the operating instructions, as an improper
adjustment of other controls may result in
damage and will often require extensive
work by a qualified technician to restore the
product to its normal operation; or
e. The product has been dropped or
damaged in any way; or
f. The product exhibits a distinct change
in performance – this indicates a need for
service.
22. Replacement Parts. When replacement
parts are required, be sure the service
technician has used replacement parts
specified by the manufacturer or that have
the same characteristics as the original part.
Unauthorized substitutions may result in fire,
electric shock or other hazards.
23. Safety Check. Upon completion of any
service or repairs to this product, ask the
service technician to perform safety checks
to determine that the product is in proper
operating condition.
24. Wall or Ceiling Mounting. The product
should be mounted to a wall or ceiling only
as recommended by the manufacturer.
25. Heat. The product should be situated
away from heat sources such as radiators,
heat registers, stoves, or other products
(including amplifiers) that produce heat.
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
CAUTION: To prevent electric shock,
do not remove the grounding plug
on the power cord, or use any plug
or extension cord that does not have
a grounding plug provided.
Make certain that the
AC outlet is properly grounded.
Do not use an adapter plug
with this product.
The lightning flash with arrowhead symbol,
within an equilateral triangle, is intended to
alert the user to the presence of uninsulated
“dangerous voltage” within the product’s
enclosure that may be of sufficient magnitude to constitute a
risk of electric shock to persons.
The exclamation point within an equilateral
triangle is intended to alert the user to the
presence of important operating and
maintenance (servicing) instructions in the
literature accompanying the appliance.
Antenna Lead-In Wire

Ground Clamp

Antenna Discharge Unit (NEC Section 810-20)

Grounding Conductors (NEC Section 810-21)

Electric Service Equipment

Ground Clamps

Power Service Grounding Electrode System
(NEC Art 250, Part H)
Figure A.
Example of Antenna
Grounding as per National
ElectricalCode, ANSI/NFPA 70
READ THIS! Important Safety Precautions! SPEAKER PLACEMENT
Part No. JBLULB 10/99
• As a general rule, bass
response increases as a
subwoofer is placed closer
to a wall. Therefore, bass
output is maximized when
the subwoofer is placed in
a corner.
• It is also recommended that
the subwoofer be
positioned along the
same wall as the front
loudspeakers.
Low-frequency sounds are
normally omnidirectional,
meaning the listener can’t tell
where they are generated
from. However, frequencies
between 75Hz – 150Hz can be
localized, especially at higher
volume levels. Positioning
your subwoofer as recom-
mended will provide the
most natural soundstage
and imaging from your
loudspeaker system.
Remember that these are just
guidelines. Since every
listening room is different,
JBL strongly recommends
experimenting with the
positioning of your subwoofer
to obtain the most pleasing
results in your room. One
technique that can help you
find the ideal subwoofer
location is to temporarily
place the subwoofer near the
main listening location. Then
move around the room and
determine where you hear
the most pleasing bass
performance. This would then
be the ideal location for the
subwoofer.
When we designed the
PB10 and PB12 powered
subwoofers, our goal was
to offer the user the best
possible performance
combined with the most
flexible and complete
installation options. Please
look over the following three
examples to determine which
description best matches your
system and follow the
corresponding hookup
instructions.
To use the binding-post
speaker terminals with bare
wire, unscrew the collar until
the hole through the center
post is visible under the collar.
Insert the bare end of the wire
through the hole in the post,
then screw the collar back
down until the connection is
tight. The holes in the center
of the collars are intended for
banana-type connectors.
Dolby* Pro Logic* (Non-Digital) – Speaker Level
Use this installation method
for Dolby Pro Logic appli-
cations (not Dolby Digital,
DTS®or other digital
processing), where the
receiver/processor does not
have a subwoofer output or
a volume-controlled preamp
(line-) level output:
Connect your receiver or
amplifier’s front left and right
speaker terminals to the left
and right terminals on the
subwoofer that are marked
“High Level In.” Connect the
left and right terminals on the
subwoofer that are marked
“High Level Out” to the cor-
responding terminals on the
back of your front left and
right speakers.
Connect your receiver or
amplifier’s center, left and
right surround-speaker
terminals to the corre-
sponding terminals on the
back of your center, left and
right surround speakers.
SPEAKER CONNECTION
Right Front
Left Front Center + –
+ – + –
Subwoofer
Right SurroundLeft Surround
+ – + –
+ –
+ –
Left Front Center
+ –
Left Surround
Right Front
+ –
Right Surround
+ –
Receiver
L
R
HIGH
LEVEL
IN
L
R
L
R
HIGH
LEVEL
OUT`
+ –

5
Dolby Pro Logic (Non-Digital) – Line Level
Use this installation method
for Dolby Pro Logic appli-
cations (not Dolby Digital, DTS
or other digital processing),
where the receiver/processor
is equipped with a subwoofer
output or a volume-controlled
preamp (line-) level output:
Use RCA-type patch cords
to connect the line-level
subwoofer outputs on your
receiver or amplifier to the
line-level inputs on the
subwoofer. IMPORTANT:
Make sure that the LFE toggle
switch on the subwoofer is in
the “Normal” position. Do not
use the “LFE” position with
Dolby Pro Logic-only
processors.
Note: If your receiver or
amplifier only has one
subwoofer output jack,
then you may connect the
subwoofer output on your
receiver/preamplifier to either
the left or right line-level input
on the subwoofer. It makes no
difference which jack you
choose.
Connect each speaker to the
corresponding speaker
terminals on your receiver or
amplifier.
Make sure your receiver or
processor is configured cor-
rectly: Make sure that the sub-
woofer is configured as “On.”
Note for advanced users: If
your receiver/processor has
a built-in low-pass crossover
filter for the subwoofer output,
then the LFE switch should be
set to the “LFE” position to
bypass the subwoofer’s
internal crossover.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L R
LFE NORMAL
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
Subwoofer
Out
RECEIVER
L
R
For LFE use L or R
L R
Dolby Digital or DTS (or Other Digital Surround Mode) Connection
Use this installation method
for Dolby Digital, DTS or other
digital surround processors:
IMPORTANT: Make sure that
the LFE toggle switch on the
subwoofer is in the “LFE”
position. Use the line-level
input jacks for the Low-
Frequency Effects channel.
Connect these jacks to the
LFE output or subwoofer
output on your receiver or
amplifier.
Note: If your receiver or
amplifier only has one
subwoofer output jack,
then you may connect the
subwoofer output on your
receiver/preamplifier to either
the left or right line-level input
on the subwoofer. It makes no
difference which jack you
choose.
Connect each speaker to the
corresponding speaker
terminals on your receiver or
amplifier.
Make sure that you have
configured your surround-
sound processor for
“Subwoofer On” or “LFE On.”
The front left, front right,
center and rear speakers
should be set to “Small” or
“Large” depending on their
size and frequency response.
Consult your receiver’s or
processor’s owner’s manual.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L R
LFE NORMAL
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
Subwoofer
Output/LFE
RECEIVER/PREAMPLIFIER
L
R
For LFE use L or R

Dolby Pro Logic (Non-Digital) – Line Level
Use this installation method
for Dolby Pro Logic appli-
cations (not Dolby Digital, DTS
or other digital processing),
where the receiver/processor
is equipped with a subwoofer
output or a volume-controlled
preamp (line-) level output:
Use RCA-type patch cords
to connect the line-level
subwoofer outputs on your
receiver or amplifier to the
line-level inputs on the
subwoofer. IMPORTANT:
Make sure that the LFE toggle
switch on the subwoofer is in
the “Normal” position. Do not
use the “LFE” position with
Dolby Pro Logic-only
processors.
Note: If your receiver or
amplifier only has one
subwoofer output jack,
then you may connect the
subwoofer output on your
receiver/preamplifier to either
the left or right line-level input
on the subwoofer. It makes no
difference which jack you
choose.
Connect each speaker to the
corresponding speaker
terminals on your receiver or
amplifier.
Make sure your receiver or
processor is configured cor-
rectly: Make sure that the sub-
woofer is configured as “On.”
Note for advanced users: If
your receiver/processor has
a built-in low-pass crossover
filter for the subwoofer output,
then the LFE switch should be
set to the “LFE” position to
bypass the subwoofer’s
internal crossover.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L R
LFE NORMAL
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
Subwoofer
Out
RECEIVER
L
R
For LFE use L or R
L R
Dolby Digital or DTS (or Other Digital Surround Mode) Connection
Use this installation method
for Dolby Digital, DTS or other
digital surround processors:
IMPORTANT: Make sure that
the LFE toggle switch on the
subwoofer is in the “LFE”
position. Use the line-level
input jacks for the Low-
Frequency Effects channel.
Connect these jacks to the
LFE output or subwoofer
output on your receiver or
amplifier.
Note: If your receiver or
amplifier only has one
subwoofer output jack,
then you may connect the
subwoofer output on your
receiver/preamplifier to either
the left or right line-level input
on the subwoofer. It makes no
difference which jack you
choose.
Connect each speaker to the
corresponding speaker
terminals on your receiver or
amplifier.
Make sure that you have
configured your surround-
sound processor for
“Subwoofer On” or “LFE On.”
The front left, front right,
center and rear speakers
should be set to “Small” or
“Large” depending on their
size and frequency response.
Consult your receiver’s or
processor’s owner’s manual.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L R
LFE NORMAL
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
Subwoofer
Output/LFE
RECEIVER/PREAMPLIFIER
L
R
For LFE use L or R
4

7
TROUBLESHOOTING
OPERATION
When the unit is plugged in
and (for the PB12 only) the
power switch is on and no
signal is received, the LEDs on
the front of the unit will turn
red. When a signal is present,
the LEDs will turn green.
Note: It will take several
minutes for the LEDs to turn
from green to red after the
input signal to the subwoofer
is removed. Due to JBL’s
unique, high-output, high-
efficiency amplifier design,
power consumption is minimal
when the subwoofer is not
receiving a signal. Of course,
the PB12 subwoofer can be
turned off, whenever desired.
The PB10 must be unplugged
if you do not wish to leave it in
auto (standby) mode.
The subwoofer Level Control
adjusts the volume of the
subwoofer relative to the rest
of the system. Proper level
adjustment depends on
several variables such as
room size, subwoofer
placement, type of main
speakers and listener position.
Adjust the subwoofer level so
that the volume of the bass
information is pleasing to you.
Crossover Adjustments
The Crossover Frequency
Control determines the highest
frequency at which the
subwoofer reproduces sounds.
If your main speakers can
comfortably reproduce some
low-frequency sounds, set this
control to a lower frequency
setting, between 50Hz – 100Hz.
This will concentrate the
subwoofer’s efforts on the
ultradeep bass sounds
required by today’s films and
music. If you are using smaller
bookshelf speakers that do not
extend to the lower bass
frequencies, set the low-pass
crossover control to a higher
setting, between 120Hz –
150Hz. This control is not used
when the LFE switch is in the
“LFE” position.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L
R
L R
For LFE use L or R
LFE NORMAL
PowerBass PB10
PowerBass PB10
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
120V
60Hz, 160W
50Hz
0º 180º
150Hz
POWER
PowerBass PB12
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
120V
60Hz, 160W
ON OFF
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L
R
L R
For LFE use L or R
LFE NORMAL
PowerBass PB12
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
If you used the high-level
(speaker) inputs and there
is no sound from any of the
speakers:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into
an active electrical outlet
and is switched on.
• Check all wires and
connections between
receiver/amplifier and
speakers. Make sure all wires
are connected. Make sure
none of the speaker wires are
frayed, cut or punctured.
• Review proper operation
of your receiver/amplifier.
If there is low (or no) bass
output:
• Make sure the connections
to the left and right “Speaker
Inputs” have the correct
polarity (+ and –).
• Make sure that the
subwoofer is plugged into an
active electrical outlet and
(PB12 only) switched on.
• Adjust the crossover point.
• Flip the Phase Control
switch to the opposite
position.
• If you are using a Dolby
Digital/DTS receiver or
processor, make sure that the
subwoofer adjustments on
the receiver/processor are
set up correctly.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
If you used the line-level
inputs and there is no sound
from the subwoofer:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into an
active electrical outlet and is
switched on.
• Check all wires and con-
nections between receiver/
amplifier and subwoofer.
Make sure all wires are
connected. Make sure none
of the wires are frayed, cut
or punctured.
• Review proper operation of
your receiver/amplifier.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
• Make sure that you have
configured your receiver/
processor so that the
subwoofer/LFE output is on.
Phase Control
The Phase Control determines
whether the subwoofer’s
piston-like action moves in
and out in phase with the
main speakers or opposite
the main speakers. There is
no correct or incorrect
setting. Proper phase
adjustment depends on
several variables such as
subwoofer placement and
listener position. Adjust the
phase switch to maximize
bass output at the listening
position.
Remember, every system,
room and listener is different.
There are no right or wrong
settings; this switch offers the
added flexibility to adjust your
subwoofer for optimum
performance for your specific
listening conditions without
having to move your
speakers. If at some time
in the future you happen to
rearrange your listening room
and move your speakers, you
should experiment with the
phase switch in both
positions, and leave it in
the position that maximizes
bass performance.
Level Control
Power

67
TROUBLESHOOTING
OPERATION
When the unit is plugged in
and (for the PB12 only) the
power switch is on and no
signal is received, the LEDs on
the front of the unit will turn
red. When a signal is present,
the LEDs will turn green.
Note: It will take several
minutes for the LEDs to turn
from green to red after the
input signal to the subwoofer
is removed. Due to JBL’s
unique, high-output, high-
efficiency amplifier design,
power consumption is minimal
when the subwoofer is not
receiving a signal. Of course,
the PB12 subwoofer can be
turned off, whenever desired.
The PB10 must be unplugged
if you do not wish to leave it in
auto (standby) mode.
The subwoofer Level Control
adjusts the volume of the
subwoofer relative to the rest
of the system. Proper level
adjustment depends on
several variables such as
room size, subwoofer
placement, type of main
speakers and listener position.
Adjust the subwoofer level so
that the volume of the bass
information is pleasing to you.
Crossover Adjustments
The Crossover Frequency
Control determines the highest
frequency at which the
subwoofer reproduces sounds.
If your main speakers can
comfortably reproduce some
low-frequency sounds, set this
control to a lower frequency
setting, between 50Hz – 100Hz.
This will concentrate the
subwoofer’s efforts on the
ultradeep bass sounds
required by today’s films and
music. If you are using smaller
bookshelf speakers that do not
extend to the lower bass
frequencies, set the low-pass
crossover control to a higher
setting, between 120Hz –
150Hz. This control is not used
when the LFE switch is in the
“LFE” position.
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L
R
L R
For LFE use L or R
LFE NORMAL
PowerBass PB10
PowerBass PB10
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
120V
60Hz, 160W
50Hz
0º 180º
150Hz
POWER
PowerBass PB12
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
120V
60Hz, 160W
ON OFF
CROSSOVER
FREQUENCY
LEVEL
LINE LEVEL IN
PHASE
Min Max
L
R
L R
For LFE use L or R
LFE NORMAL
PowerBass PB12
HIGH
LEVEL
IN
L
R
HIGH
LEVEL
OUT
+ –
50Hz
0º 180º
150Hz
If you used the high-level
(speaker) inputs and there
is no sound from any of the
speakers:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into
an active electrical outlet
and is switched on.
• Check all wires and
connections between
receiver/amplifier and
speakers. Make sure all wires
are connected. Make sure
none of the speaker wires are
frayed, cut or punctured.
• Review proper operation
of your receiver/amplifier.
If there is low (or no) bass
output:
• Make sure the connections
to the left and right “Speaker
Inputs” have the correct
polarity (+ and –).
• Make sure that the
subwoofer is plugged into an
active electrical outlet and
(PB12 only) switched on.
• Adjust the crossover point.
• Flip the Phase Control
switch to the opposite
position.
• If you are using a Dolby
Digital/DTS receiver or
processor, make sure that the
subwoofer adjustments on
the receiver/processor are
set up correctly.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
If you used the line-level
inputs and there is no sound
from the subwoofer:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into an
active electrical outlet and is
switched on.
• Check all wires and con-
nections between receiver/
amplifier and subwoofer.
Make sure all wires are
connected. Make sure none
of the wires are frayed, cut
or punctured.
• Review proper operation of
your receiver/amplifier.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
• Make sure that you have
configured your receiver/
processor so that the
subwoofer/LFE output is on.
Phase Control
The Phase Control determines
whether the subwoofer’s
piston-like action moves in
and out in phase with the
main speakers or opposite
the main speakers. There is
no correct or incorrect
setting. Proper phase
adjustment depends on
several variables such as
subwoofer placement and
listener position. Adjust the
phase switch to maximize
bass output at the listening
position.
Remember, every system,
room and listener is different.
There are no right or wrong
settings; this switch offers the
added flexibility to adjust your
subwoofer for optimum
performance for your specific
listening conditions without
having to move your
speakers. If at some time
in the future you happen to
rearrange your listening room
and move your speakers, you
should experiment with the
phase switch in both
positions, and leave it in
the position that maximizes
bass performance.
Level Control
Power

Electrical Parts List - PB12
PB12 POWERAMP PCB Version 6.3.
Part# Designator Description
50100 BR RECT RS604 6AMP Bridge rectifier
50105 D1 1N4744A 15V 1w Zener
50112 D10 1N5242B 12V .5w Zener
50104 D11 1N4148 Sig Diode
50112 D12 1N5242B 12V .5w Zener
50104 D13 1N4148 Sig Diode
50104 D14 1N4148 Sig Diode
50105 D2 1N4744A 15V 1w Zener
50114 D3 1N5265B 62V .5w Zener
50104 D4 1N4148 Sig Diode
50113 D5 1N4735A 6.2V 1W
50103 D6 1N5234B 6V .5w Zener
50104 D7 1N4148 Sig Diode
50104 D8 1N4148 Sig Diode
60157 Q1 2N5457 25V N-chnl FET
60155 Q10 2N5401 120V PNP 600mA
60155 Q11 2N5401 120V PNP 600mA
60156 Q12 2N4401 40V NPN 600mA
60102 U1 TLO64 Quad OpAmp
Capacitors
30710 C1 2200uF 100V +80 / -20 Electrolytic 105C
30718 C10 4u7F 100V BP/NP Electr DF<.1
30523 C11 330nF 100V mono ceramic
30710 C2 2200uF 100V +80 / -20 Electrolytic 105C
30532 C20 220nF 250V metallized polyester
30502 C21 100nF 50V mono ceramic
30502 C22 100nF 50V mono ceramic
30527 C24 330nF 50V mono ceramic
C25 NOT USED
30508 C26 10nF 50V mono ceramic
30513 C27 3n3F 50V mono ceramic
30502 C3 100nF 50V mono ceramic
30711 C32 22uF 35V +80/-20 Electrolytic
30715 C40 10uF 16V +80/-20 Electrolytic
30716 C41 1uF 16V +80/-20 Electrolytic
30717 C42 100uF 16V +80/-20 Electrolytic
30502 C6 100nF 50V mono ceramic
30521 C7A 100nF 250V ceramic/film
30521 C7B 100nF 250V ceramic/film
CW NOT USED
30505 CZ 100nF 100V ceramic/film
10

Part# Designator Description
Resistors
R100 NOT USED
40105 R10A 0.1R .5W metal
40105 R10B 0.1R .5W metal
40105 R10C 0.1R .5W metal
40420 R11 1k .25W carbon
40420 R12 1k .25W carbon
40417 R13 47k .25W carbon
40718 R14 3k3 .25W carbon
R15 NOT USED
40735 R1A 7k5 2W metal
40735 R1B 7k5 2W metal
40735 R1C 7k5 2W metal
40405 R21 4K7 .25W carbon
40736 R22 42K2 .25W metal
40737 R23 187k .25W metal
R24 NOT USED
R25 NOT USED
40722 R26 6k8 .25W carbon
40738 R27 10k 2W metal
40739 R28 1k2 0.25W carbon
40739 R29 1k2 0.25W carbon
40735 R2A 7k5 2W metal
40735 R2B 7k5 2W metal
40735 R2C 7k5 2W metal
40703 R3 8M2 .25W carbon
40738 R30 10k 2W metal
40417 R31 47k .25W carbon
40417 R32 47k .25W carbon
40427 R33 23k7 .25W metal
40403 R34 10k .25W metal
40740 R4 33k 1W metal
40420 R40 1k .25W carbon
40701 R41 1000k .25W carbon
40741 R42 22k .5W metal
40701 R43 1000k .25W carbon
40406 R44 100k .25W carbon
40415 R45 470K .25W carbon
40701 R46 1000k .25W carbon
40409 R47 10k .25W carbon
40409 R48 10k .25W carbon
40726 R49 15k .25W carbon
40732 R5 56k2 .25W metal
40727 R50 2k2 .25W carbon
40111 R6 47R .25W carbon
40738 R7A 10k 2W metal
11

Part# Designator Description
40738 R7B 10k 2W metal
40738 R7C 10k 2W metal
40738 R8A 10k 2W metal
40738 R8B 10k 2W metal
R9 NOT USED
Miscellaneous
80121 L1 220uH 5 Amp Gapped Ecore choke
80122 L2 8u5H 5 Amp ferrite bead
80122 L3 8u5H 5 Amp ferrite bead
80122 L4 8u5H 5 Amp ferrite bead
80100 CMC 2m2H 5 Amp choke
60302 MODULE S64AMI
108326 Led Harness
With two LED's,Molex plug
Glued into cabinet
80116 Transformer MCI4632 100VA 4632 transformer
70151 Switch SW SPST Power Switch
70322 LED socket PCB mount LED socket
80117 3AG FUSE 2A SloBlo T type
70324 0.187" PCB Tabs 7
70323 PCB Fuse Holders 2
70325 PB12 faceplate PB12 faceplate
80105 Power cord Power cord
70305 Strain relief Strain relief
PB12 PREAMP PCB Version #6.3
Part# Designator Description
Semiconductors
60102 U1 TLO 64 OP amp
60100 U2 LM324 OP amp
Capacitors Film Caps may be used in any position EXCEPT C1,C2
30707 C1 200uF 50V BP Electrolytic
30504 C10 100nF 50V mono ceramic
30504 C11 100nF 50V mono ceramic
30504 C12 100nF 50V mono ceramic
30504 C13 100nF 50V mono ceramic
30530 C16 100nF 50V mono ceramic
30531 C17 150nF 50V mono ceramic
30100 C18 330pF 50V mono ceramic
30100 C19 330pF 50V mono ceramic
30707 C2 200uF 50V BP Electrolytic
30502 C20 100nF 50V mono ceramic
12

Part# Designator Description
30502 C21 100nF 50V mono ceramic
30502 C22 100nF 50V mono ceramic
30502 C23 100nF 50V mono ceramic
30101 C3 220pF 50V mono ceramic
C30 NOT USED
30101 C4 220pF 50V mono ceramic
30101 C5 220pF 50V mono ceramic
30101 C6 220p 50V mono ceramic
C7 0r
C8 0r
40730 C9 1k .25W Metal Resistor
Resistors
40405 R1 4k7 .25W carbon
40409 R10 10k .25W carbon
40731 R11 59k .25W carbon
40504 R12 45k3 .25W metal
40412 R13 33k2 .25W metal
40709 R14 68k1 .25W metal
R15 NOT USED
R16 NOT USED
40732 R17 56k2 .25W metal
40722 R18 6k8 .25W carbon
40722 R19 6k8 .25W carbon
40405 R2 4k7 .25W carbon
40722 R20 6k8 .25W carbon
R21 0r
40722 R22 6k8 .25W carbon
R23 0r
40109 R24 604r .25W metal
40412 R25 33k2 .25W metal
40405 R26 4k7 .25W metal
40109 R27 604r .25W metal
40412 R28 33k2 .25W metal
40406 R3 100k .25W carbon
40403 R30 10k .25W metal
40733 R33 12k1 .25W metal
40734 R34 120k .25W metal
40451 R35 137k .25W metal
40406 R4 100k .25W carbon
40406 R5 100k .25W carbon
40406 R6 100k .25W carbon
40717 R8 2k7 .25W carbon
40717 R9 2k7 .25W carbon
13

Miscellaneous
108320 RCA CONNECTOR DUAL RCA-yellow
108116 HI LEVEL I/O Binding Post OUT Binding Post
108116 HI LEVEL I/O Binding Post IN Binding Post
40402 LEVEL 5k POT Log (A) Pot
40707 Crossover CONTROL 20k POT Lin (B) Pot.
70150 LFE switch SW SPDT mini-Toggle
70150 Phase Switch SW SPDT mini-Toggle
14

PB12 MECHANICAL & PACKING PARTS LIST
Part# Description
203500 12” Woofer
203410 Foot
203520 Outer Carton
203430 Owner’s manual 120V
203550 Amplifier complete
15

V
ers63.gbl (Board layer 1) Scale=1.20 Wed May 17 08:26:14 2000

V
ers63.gtl (Board layer 1) Scale=1.20 Wed May 17 08:36:44 2000

V
ers63.gto (Board layer 1) Scale=1.36 Wed May 17 08:38:34 2000

1 2 34
A
B
C
D
4
321
D
C
B
ATitle
Number RevisionSize
Tabloid
Date: 20-Apr-2000 Sheet of
File: T:\PB12 sch Folder\..\PB12 preamp Rev5.schDrawn By:
1
2
3
4
5
6
Un-designated Connector
NOT USED
U1
U2 U1
TLO64
U1
R16
NOT USED
C9
1k
C8
0r
C7
0r
R15
NOT USED
R17
56k2
R14
68k1
R35
137k
R13
33k2
R9
2k7 C5
220pF
C3 220pF
C2
200uF
C1
200uF
8
10
9
R27
604r
R34
120k
R24
604r
R28 33k2
C19 330pF
C18 330pF
R10
10k
R11
59k C6
220p
R In
GND
L In
R6
R5
R4
R3
100k
R8
2k7
C4
220pF
Phase Switch
SW SPDT
LEVEL
5k POT
R12
45k3
U2
LM324
U2
C17
150nF
C16
100nF
R30
10k
R26
4k7
R33
12k1
1
3
2
2
3
1
R18
6k8
R20
6k8
U1
U2
C10
100nF
C12
100nF
C13
100nF
C11
100nF
R21
0r
R19
6k8
R22
6k8
R23
0r
LoPass Defeat Sw.
SW SPDT
13
12
14
13
14
12
3
2
17
6
5
6
5
7
8
10
9
1
3
2
1
2
3
1
2
3
4
5
6
7
8
9
11
12
10
R1
4k7
R2
4k7
+15V
-15V
C21
100nF
C20
100nF
C23
100nF
C22
100nF
+15V
GND
GND
SIG
-15V
mute
To/From PWRAMP
R25 33k2
B12 PREAMP (6.3 pcb)
5
11
MS/LL
3rd Order Hi-Pass
2nd Order LO-PASS
2nd Order LO-PASS
GAIN STAGE
RCA CONNECTOR
DUAL RCA
1
2
3
REMOTE Pot
NOT USED
R
L
B-POST HiLev I/O
IN
R
L
OUT
C30
NOT USED
2nd Order Hi-Pass
To Pin 11 U1/U2
To Pin 14 U1/U2
+15V
-15V
LO PASS CONTROL 1
20k POT
LO PASS CONTROL 2
20k POT
LO PASS CONTROL 3
NOT USED
LO PASS CONTROL 4
NOT USED
+15V
-15V
From PwrAmp
From PwrAmp
NOT USED
1
2
LED1
NOT USED
1
2
Led Harness
NOT USED
LED 2
NOT USED