JBL HTPS-400, Service Manual, Page: 14 / 32

HTPS-400 SUBWOOFER
14
Test Set Up and Procedure
General Function (UUT = Unit Under Test)
1. Connect a single (RCA) cable from the signal generator to the "line in" jack on the UUT.
GAIN control should be full counterclockwise.
Off/Auto/On switch should be OFF.
EQ switch should be on Normal.
Turn Crossover knob to full CW (150)
Position of phase switch is irrelevant.
2. Turn on generator, adjust to 200mV, 30 Hz.
3. Plug in UUT; red LED should be ON. Turn GAIN control full clockwise.
4. Bass response should be substantial, and woofer at near maximum excursion.
5. Turn off generator, turn VOLUME control fully counterclockwise, disconnect RCA cable.
Sweep Function
1. Follow steps 1-4 above, using a sweep generator as a signal source.
2. Sweep generator from 20Hz to 300Hz. Listen to the cabinet and drivers for any rattles, clicks,
buzzes or any other noises. If any unusual noises are heard, remove driver and test.
Driver Function
1. Remove driver from cabinet; and - wire clips.
2. Check DC resistance of driver; it should be 8.1 ohms ±10%.
3. Connect a pair of speaker cables to driver terminals. Cables should be connected to an integrat-
ed amplifier fed by a signal generator and adjust so that speaker level output is 5.0V.
4. Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual
noises.
SIGNAL
GENERATOR
AC VOLT
METER (6V)
HTPS-400
UNDER TEST
00367
00368