JBL 1500 ARRAY, Service Manual

Page: 10 / 28

1500 Array TEST PROCEDURE
Equipment needed:
•
Function/signal generator/sweep generator
•
Multimeter
•
RCA cable
General Unit Function (UUT = Unit Under Test)
Switch/Controls:
GAIN control full Counterclockwise (Min)
CROSSOVER (Hz) Full Clockwise (140)
PHASE switch - either position
LFE/LP – LP position
1) From the signal generator, connect one line level (RCA) cable to the Line In jack on the UUT.
2) Turn on generator; adjust to
200mV, 50 Hz .
3) Plug AC power cord in UUT, turn power switch ON.
4) LED should be ON (faceplate). Turn up LEVEL control to full Clockwise (Max).
5) LED should be Green; Bass response should be heard and felt vigorously from woofer and port tube.
6) Turn LEVEL control full Counterclockwise (Min). Turn power switch OFF.
Sweep Function
1) Follow steps 1-5 above, using a sweep generator as a signal source – adjust the generator to 75mV, 50 Hz .
2) Sweep generator from 20Hz to 300Hz. Listen for any rattles, clicks, buzzes or any other noises. If any unusual
noises are heard, test woofer according to the instructions below.
Driver Function
1) Remove woofer from the enclosure.
2) Check DC resistance of woofer; it should be
5.9
Ω
±10%,
3) Connect a pair of speaker cables to woofer 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 6.0V.
4) Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.
9
1500 Array Subwoofer