Test Set Up And Procedure - Infinity INTERMEZZO 1.2s Service Manual

INTERMEZZO 1.2s
SIGNAL
GENERATOR
AMPLIFIER
The operation of the Intermezzo 1.2s subwoofer,and the proper settings for the Room Adaptive Bass Opitmization System, or
R.A.B.O.S., is thoroughly covered in the Owner's guide, part #336204-001.
For service purposes, the R.A.B.O.S. system is canceled when all three front panel controls (F) (L) (W) are turned fully CW
(Clockwise).
The only other control of concern is the Main Level Control on the front panel, which operates like a traditional potentiometer.
Equipment needed:
• Function/signal generator/sweep generator
• Integrated Amplifier
• Multimeter
• RCA cables; Speaker cables
General Unit Function (UUT = Unit Under Test)
Switch/Controls:
MAIN LEVEL control full clockwise (0)
LOW PASS FILTER knob full clockwise (130 Hz)
LOW PASS FILTER button OFF (depressed)
HIGH PASS FILTER button OFF (depressed)
PHASE button - either position
1) From the signal generator, connect one line level (RCA) cable to the IM1.2s Low Level Input jacks (L/R) on the UUT. Use a
Y-cable from a mono source if necessary to connect to both inputs.
2) Turn on generator, adjust to 140mV, 50 Hz.
3) Plug AC power cord in UUT, turn power switch ON.
4) Red LED should ON (in the Level wheel at the front of the UUT). Turn up LEVEL control to full counterclockwise (10).
5) Green LED should ON; Bass response should be heard and felt.
6) Turn LEVEL control full clockwise (0). Turn power switch OFF.
7) Connect one pair of speaker cables to one set (either R or L) of the Speaker input terminals on UUT. Cables should be
connected to an integrated amplifier fed by the signal generator.
8) Turn on signal generator and adjust so that speaker level output at the amplifier is 7.0V, 50 Hz.
9) Turn power switch ON; turn LEVEL control full counterclockwise (10).
10) Bass response should be heard and felt.
Sweep Function
1) Follow steps 1-3 above, using a sweep generator as a signal source – adjust the generator to 100mV, 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; (instructions in exploded view on page 12);
2) Check DC resistance of woofer; it should be 7.6 ohms ±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.

Test Set Up and Procedure

AC VOLT
METER (10V)
INTERMEZZO 1.2s
UNDER TEST
SPEAKER
OUTPUT
FROM
AMPLIFIER
14