Infinity HPS-250, Technical Manual

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6
Powered Subwoofer HPS-250
TEST PROCEDURE 2
(Note: A high gain amplifier of at least a 100 watt rating is recommended for this test)
General Function
UUT = Unit Under Test
1. Connect both right and left line level inputs (RCA) to signal generator and UUT. Use Y-cable if necessary from
mono source. GAIN control should be full counterclockwise.
2. Turn on generator, adjust to 100mV, 50 Hz.
3. Plug in power cord to UUT; push the main ACpower button ON. Green LED should be lit.
4. Turn GAIN control full clockwise; immediate bass response should be heard and felt from port tube opening.
5. Turn off generator, turn GAIN control fully counterclockwise, disconnect RCA cables.
6. Connect one pair of speaker cables to either pair (R) or (L) input terminal on UUT. Cables should be connected to
an integrated amplifier fed by the signal generator.
7. Turn on generator and adjust so that speaker level output is 2.0V, 50 Hz .
8. Turn GAIN control full clockwise; immediate bass response should be heard and felt from the port tube opening.
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 following instructions on page 5.
2. Check DC resistance of driver; it should be 21 ohms +/-10%.
3. 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
30.0V.
4. Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.