Thursday, December 11, 2014

JBL BALBOA SERIES Powered SUB-10 – CIRCUIT DIAGRAM – (Schematic) - Troubleshooting

JBL SUB-10 _ POWERED SUB-WOOFER _ SCHEMATIC _ [Circuit Diagram] _ Troubleshooting flow chart
Specifications
Amplifier Power (RMS): 100 Watts
Peak Dynamic Power : 225 Watts
Driver: 10" (254mm)
Inputs: Line Level and LFE
Crossover Frequency: Variable from 50Hz to 150Hz, 24 dB per octave
Frequency Response: 30Hz – 150Hz
Dimensions (H x W x D):
19-3/4" x 14-1/16" x 14-3/4" (502mm x 357mm x 375mm)
Weight: 35 lb/16kg
General Unit Function (UUT = Unit Under Test)
* Switches/knobs on the amplifier face-plate:
* Low Pass Frequency Adjust full CW (150Hz)
* Phase switch – either position
* From the signal generator, Connect both right and left line level inputs (RCA) – not the LFE jack - to signal generator and UUT. Use Y-cable if necessary from mono source.
* On the amplifier, turn the LEVEL control full Counterclockwise (Min).
Turn on generator, adjust to 100mV, 50 Hz.
* Plug in UUT; turn the power switch ON. Turn LEVEL control full Clockwise (Max).
LED should now be Green; immediate bass response should be heard and felt from rear port tube opening.  Turn off generator, turn LEVEL control fully Counterclockwise (Min), disconnect RCA cable.
Sweep Function
Follow steps above, using a sweep generator as a signal source.
Sweep generator from 20Hz to 1kHz. Listen to the cabinet and drivers for any rattles, clicks, buzzes or any other noises. If any unusual noises are heard, remove woofer and test.
Driver Function (Woofer)
* Remove woofer from cabinet; detach + and - wire clips.
* Check DC resistance of woofer; it should be 3.3 ohms ±10%.
* Connect a pair of speaker cables to driver terminals. Cables should be connected to an integrated amplifier fed by a signal generator. Turn on generator and adjust so that speaker level output is 5.0V.
Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.
Adjust Level
Turn your Sub-woofer-Level Control up to the “5” position (halfway). If no sound emanates from the sub-woofer, check the AC-line cord and input cables. Are the connectors on the cables making proper contact? 

Is the AC plug connected to a “live” receptacle? 
Has the Power Switch  been pressed to the “On” position? 
Once you have confirmed that the sub-woofer is active, proceed by playing a CD, record or cassette. Use a selection that has ample bass information.
Set the overall volume control of the pre-amplifier or stereo to a comfortable level. Adjust the Sub-woofer-Level Control  until you obtain a pleasing blend of bass. Bass response should not overpower the room but rather be adjusted so there is a harmonious blend across the entire musical range. Many users have a tendency to set the sub-woofer volume too loud, adhering to the belief that a sub-woofer is there to produce lots of bass. This is not entirely true.  A sub-woofer is there to enhance bass, extending the response of the entire system so the bass can be felt as well as heard. However, overall balance must be maintained or the music will not sound natural. An experienced listener will set the volume of the sub-woofer so its impact on bass response is always there but never obtrusive.
Phase Control
The Phase Switch determines whether the sub-woofer speaker’s piston-like action moves in and out with the main speakers (0˚), or opposite the main speakers (180˚). Proper phase adjustment depends on several variables such as room size, sub-woofer placement and listener position. 

Adjust the phase switch to maximize bass output at the listening position.  Crossover Adjustments  The Crossover Adjustment Control  determines the highest frequency at which the sub-woofer reproduces sounds. If your main speakers can comfortably reproduce some low-frequency sounds, set this control to a lower frequency setting, between 50Hz and 100Hz. This will concentrate the sub-woofer’s efforts on the ultra deep 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 Crossover Adjustment Control to a higher setting, between 120Hz and 150Hz.
NOTE: This control will have no effect if the LFE Input ¢
is used. If you have a Dolby Digital or DTS processor/receiver, the Low-Pass Frequency is set by the processor/receiver. Consult your owner’s manual to learn how to view or change this setting.
EXPLODED VIEW
SCHEMATICS
Troubleshooting
CLICK ON THE PICTURES TO MAGNIFY