JBL S120PII User Manual

Studio™ Series

S120P

II

Powered Subwoofer

Service Manual

JBL Consumer Products
250 Crossways Park Dr.

Woodbury, New York 11797 Rev

3 2/2006

- CONTENTS -

1

BASIC SPECIFICATIONS …………….……..…………..1
DETAILED SPECIFICATIONS ……….……..…………..2
CONNECTIONS………………………...……..…...…..…4
OPERATION ……..………………….……...…….….…...7
BASIC TROUBLESHOOTING..…………………… ……8
BULLETIN JBL2003-06………..…………….………..….9
S120PII AMPLIFIER BLOCK DIAGRAM………………10

S120PII EXPLODED VIEW…………….…………….....11

S120PII TEST SET UP AND PROCEDURE….……....12

S120PII ELECTRICAL PARTS LIST ..……….…….….13
P.C. B . D R AWIN G S….……………………………...…….20
S120PII IC/TRANSISTOR PINOUTS..……..….…….….22
S120PII SCHEMATICS………..…………….……….….23

S120PII PACKAGE……………………………………....27

JBL S120PII SPECIFICATIONS

Amplifier Power (RMS): 400 Watts
Driver: 12" PolyPlas™ (polymer-coated cellulose

fiber) (4.4 o hms DCR)

Inputs: Line Level (switchable to LFE), BassQ™ and

Speaker Level

Outputs: BassQ and Speaker Level (High-Pass)
Low-Pass Frequency: Continuously variable from 50Hz – 150Hz
High-Pass Frequency: 150Hz when using speaker-level outputs
Frequency Response: 22Hz – Low-pass crossover setting
Dimensions (H x W x D): 17-3/16" x 16-3/16" x 18" (19" with grille)

(with feet, without spikes) 437 x 411 x 457mm (483mm with grille)
Weight: 56 lb/25.5kg

All features and specifications are subject to change without notice.

(

S120PII Studio Series

2

S120PII 300W Powered Sub/ Plate Amp

LINE VOLTAGE Yes/No Hi/Lo Line Nom. Unit Notes

Parameter Spec Unit
Amp Section

Type (Class AB, D, other) D n/a n/a
Load Impedance (speaker) 6 Ohms n/a Nominal

Rated Output Power 275 Watts 220 1 input driven
THD @ Rated Power 0.1 % 1 22k filter
THD @ 1 Watt 0.1 % 0.5 22k filter
DC Offset 10 mV-DC 60 @ Speaker Outputs

Damping factor >50 DF 23 Measured at amplifier board

Input Sensitivity

Input Frequency 50 Hz 50 Nominal Freq.
L&R 425 mVrms ±2dB To 200 Watts Single input driven
LFE Mode selected 425 mVrms ±2dB To 200 Watts LFE Mode selected, single input driven
Bass Q Input 0.9 Vrms ±2dB To 200 Watts Single input driven
Speaker/Hi Level Input 5.5 Vrms ±2dB To 200 Watts Single input driven

Signal to Noise

SNR-A-Weighted 100 dBA 85 relative to rated power A-Weighting filter
SNR-unweighted 90 dBr 85 relative to rated power 22k filter
SNR rel. 1W-unweighted 65 dBr 60 relative to 1W Output 22k filter

Residual Noise Floor 1 mVrms 2

Residual Noise Floor 1 mVrms

US 120vac/60Hz Yes 108-132 120 Vrms Normal Operation

EU 230vac/50-60Hz Yes 207-264 230 Vrms Normal operation, MOMS required

QA Test

Limits Conditions Notes

Bridge type amplifier, None of the speaker
terminals must be connected to system GND at
any time.

Limiter prevents continuous power to exceed
220 Watts.

Measured at the speaker cable. 200 Watts,
measured at speaker output terminals located at
the amp board.

Volume @max, using RMS reading
DMM/VOM (or A/P)
Volume @max, w/ A/P Swept
Bandpass Measurement (Line

max)2

freq.+ harmonics)

Input Impedance

Filters

LP 4th order fixed 50-150 Hz ± 10 2nd order variable and 2nd order fixed
Subsonic filter (HPF) 3rd Order Fixed
LFE Low pass 2nd order Fixed Hz ± 10 LFE input driven only

Limiter

THD at Max. Output Power YES n/a functional Maximum Output Power

Features -­Auto - On -Off switch YES -- functional Refer to ATO section
Phase switch 0-180 deg functional
Volume pot Taper (lin/log) LOG -- functional A Taper
Variable crossover 50-150 Hz YES functional

HP Speaker out functional
LFE -Normal Select switch YES -- functional Disables LP filter, intended for LFE
BassQ Input YES functional 6.3mm Phono Jack

BassQ Output YES functional Bypass, loop-through - Designed for daisy chain

Input Configuration

Line In (L,R) & LFE YES
Bass Q in YES
Spkr/Hi Level In YES -- functional Binding post connector L&R

Signal Sensing (ATO)

Auto-Turn-On (yes/no) YES functional Auto - on selection switch in Auto
ATO Input test frequency 50 Hz functional "
ATO Level LFE Input 2 mV functional "
ATO Level Speaker in 50 mV functional "
ATO Level Bass Q input 2 mV functional "

ATO Turn-on time 1 seconds functional

Auto Mute/ Turn-OFF Time 15 minutes 17

Line Input (L, R,LFE) 10K ohms n/a Nominal

Speaker/Hi Level Input 10K ohms n/a Nominal

-- functional Dual RCA jack
functional 6.3m phono mono Jack

Amp connected and AC on, then
input signal applied
T before muting, after signal is
removed

HP single order filter 180 Hz @ 8 Ohms, 90 Hz
@ 4 Ohms load

Auto turn of time (T) must be 10 > T < 17
Minutes

Power on Delay time 3 sec. 4 AC Power Applied

S120PII Studio Series

3

Parameter Spec Unit

Transients/Pops

ATO Transient 5 mV-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 70 % 65 Rated power Nominal Line voltage 120 VAC

Stand-by Input Power 12 Watts 15 @ nom. line voltage
Power Cons. @ rated power 400 Watts 400 @ nom. line voltage 250 Watts @ 6.0 Ohms nominal line voltage

Protection

Short Circuit Protection YES functional Direct short at output

Thermal Protection YES functional @1/8 max unclipped Power
DC Offset Protection YES - DC present at Speaker Out leads Relay or crowbar (for driver/fire protection),
Line Fuse Rating
USA-Domestic 4 Amps Type-T or Slo Blo-250 V
EU 2 Amps Type-T or Slo Blo-250 V Internal fuse with UL/SEMKO rated holder

QA Test

Limits Conditions Notes

Maximum allowable input power under nominal
Input voltage and frequency, in stand-by mode
(HOT or COLD operation).

Amplifier should resume operation after short
circuit condition removal
Temperature rise in accessible metal parts
should not exceed 35K rise for domestic version
or 30K rise for European versions

When we designed the
S120PII powered subwoofer,
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

•ª with
bare wire, unscrew the collar
until the pass-through hole in
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 appli­cations (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:

If your receiver features bass
management capabilities that
require you to configure your
speaker settings, make sure
to set your left- and right-front
speakers to “LARGE”.

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” ª
to the corresponding
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 corre­sponding terminals on the
back of your center, left and
right surround speakers.

SPEAKER CONNECTION

S120PII Studio Series

4

Left Front

+ –

Center

+ –

Subwoofer

+ –

Right Front

+ –

L

L

HIGH
LEVEL

IN

R

R

L

HIGH
LEVEL
OUT`

R

Left Front Center

+ – + –

Receiver

Right Front

+ –

Left Surround

+ –

+ –

Right Surround

+ –

Right SurroundLeft Surround

+ –

•

ª

Dolby Pro Logic (Non-Digital) – Line Level

Use this installation method
for Dolby Pro Logic appli­cations (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 cor­rectly: Make sure that the sub­woofer 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.

Subwoofer

Out

RECEIVER

L R

HIGH

LEVEL

IN

HIGH

LEVEL

OUT

L

R

L

R

+ –

IN OUT R L

CROSSOVER
FREQUENCY

BASSQ

(See owner’s

manual

before use)

LINE

LEVEL IN

(For LFE

use R or L)

LEVEL

PHASE AUTO

50Hz

80Hz

180°0°LFE

NORMALONOFF

150Hz

MIN

MAX

¡

¢
∞

§
¶

•

ª

™

£

5

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 Low­Frequency Effects channel.
Connect these jacks to the
LFE output or subwoofer
output on your receiver or
amplifier.

Note: If your receiver or
amplifier has only 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.

HIGH

LEVEL

IN

HIGH

LEVEL

OUT

L

R

L

R

+ –

IN OUT R L

CROSSOVER
FREQUENCY

BASSQ

(See owner’s

manual

before use)

LINE

LEVEL IN

(For LFE

use R or L)

LEVEL

PHASE AUTO

50Hz

80Hz

180°0°LFE

NORMALONOFF

150Hz

MIN

MAX

¡

¢
∞

§

¶

•

ª

™

£

Subwoofer
Output/LFE

RECEIVER/PREAMPLIFIER

BassQ™Jacks

S120PII Studio Series

6

The jacks marked “BassQ” §
are for use with the JBL
BassQ bass equalization
module that will be released
in the near future. The BassQ
will enable you to optimize

your system’s bass response
by equalizing the output of
multiple subwoofers to
best match your listening
environment.
nect these jacks to any other

DO NOT con-

device. Do not use the BassQ
jacks § without having first
read the BassQ owner’s
manual.

OPERATION

The S120PII is equipped with
both a master Power switch
‚ and an Auto turn-on/turn­off switch £. In order to
function, the S120PII must
be plugged into an active
electrical outlet (but not an
accessories outlet on another
component of your audio
system such as a receiver),
and the master Power switch
‚ must be turned on
(the “•” position).
The Auto turn-on/turn-off
switch £ has three positions:
On The subwoofer is on at

all times and ready to
play program material.

Auto As long as no audio

signal is received, the
subwoofer is in Standby
mode to conserve
power, indicated by the
red color of the LEDs on
the front of the unit.
When an audio signal is
sensed, the subwoofer
will switch itself into the
fully On mode and begin
playing the program
material. The LEDs will
turn green. When a
period of about twenty
minutes goes by during
which no signal is
sensed, the S120PII will

return to Standby mode,
indicated by the LEDs
turning red.

Off The subwoofer is off at

all times, even if an
audio signal is present

at its inputs.
If you plan to be away for an
extended time, or if the
subwoofer will not be used,
you may wish to turn off the
master Power switch ‚.

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.

When using a Dolby Digital/
DTS receiver, adjust the LFE
level on the receiver to 0dB,
and then adjust the subwoofer
Level Control ∞ for the
desired amount of bass.

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.

Level Control

Power

S120PII Studio Series

7

£

™

¡

180°0°LFE

PHASE AUTO

NORMALONOFF

80Hz

CROSSOVER

¢

FREQUENCY

BASSQ

(See owner’s

manual

before use)

50Hz

IN OUT R L

∞

§

¶

•

ª

150Hz

+ –

LEVEL

MAX

MIN

L

HIGH
LEVEL

R

L

HIGH
LEVEL

R

LINE
LEVEL IN
(For LFE

use R or L)

IN

OUT

S120P

II

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK,
DO NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.

AVERTISSEMENT: POUR PRÉVENIR LES RISQUES D’INCENDIE OU
DE CHOC ÉLECTRIQUE ÉVITER D’EXPOSER CET APPAREIL A LA
PLUIE OU A L’HUMIDITÉ.

ON

‚

OFF

TROUBLESHOOTING

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.
Make sure no wires are
touching other wires or
terminals and creating a
short circuit.

• 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
that both power switches
are 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. When using
the S120P

II’s Speaker Level

inputs •, you should set your
receiver to configure the
main left and right speakers
as “LARGE”.

• 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
that both Power switches
are on

£‚.

• Check all wires and con­nections 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.

S120PII Studio Series

8