INTERMEZZO 4.1t
12
Test Setup and Procedure
SYSTEM AURAL SWEEP TEST
Equipment needed:
• Function/signal generator/sweep generator
• Integrated amplifier
• Multimeter
• Speaker cables & single RCA phono cable
General Unit Function (UUT = Unit Under Test)
For service purposes, cancel the R.A.B.O.S. system by turning all three front panel controls (F) (L) (W) fully clockwise
with a small screwdriver. You may want to take note and count the “detents” to be able to set the customer’s system
back the way it was before the test.
Position of the Bass Mode switch: initially, switch should be in position 1.
1. From the signal generator, connect one line-level (RCA) cable to the IM 4.1t Line-Level Input jack on the UUT.
2. On the front of the unit, turn the LEVEL control full clockwise (0).
3. Turn on generator; adjust to 200mV, 45Hz.
4. Plug in UUT; turn the power switch ON. LED should be Red. Turn LEVEL control full counterclockwise (10).
5. LED should now be Green; vigorous bass response should be seen at the woofer (with grille removed).
6. Turn off generator, turn LEVEL control fully clockwise (0), and disconnect RCA cable.
7. Connect one pair of speaker cables to Speaker Level input terminal on UUT. Cables should be connected to an
integrated amplifier fed by the signal generator.
8. Bass Mode switch should now be set to position 3.
9. Turn on generator and adjust so that Speaker Level input at the amplifier is 7.0V, 45Hz. Turn LEVEL control fully
counterclockwise (10)
10. Green LED should light, vigorous bass response should be seen at the woofer (with grille removed).
Sweep Function
1. Follow steps 7 – 10 above, using a sweep generator as a signal source.
2. Sweep generator from 20Hz to 20kHz. 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)
1. Remove woofer from cabinet, following instructions on page 14; detach + and – wire clips.
2. Check DC resistance of woofer; it should be 7.6 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 5.0V.
4. Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing or other unusual noises.