JBL Balboa SUB10, Service Manual

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SUB10 Test Set Up and Procedure
Equipment needed:
• Function/signal generator/sweep generator
• Integrated Amplifier
• Multimeter
• Speaker cables
General Unit Function (UUT = Unit Under Test)
1) From the signal generator, connect line level (RCA) cables to the Subwoofer Line Level Input jacks L/R on
the UUT. Use a Y-cable from a mono source if necessary to connect to both inputs. Do not connect to the
single LFE input.
2) Turn the CROSSOVER control to maximum (150).
3) Turn the LEVEL control on the UUT to completely counterclockwise (MIN).
4) Turn on generator; adjust to
100mV, 50 Hz
.
5) Plug in UUT; turn the power switch ON. LED should switch from Red to Green.
6) Turn LEVEL control full clockwise (MAX); immediate and vigorous bass response should be heard and felt
from port tube opening on the bottom.
7) Turn off generator, turn LEVEL control full counterclockwise (MIN), and disconnect RCA cable.
8) Connect one pair of speaker cables to Speaker Level input terminal (IN) on UUT. Cables should be
connected to an integrated amplifier fed by the signal generator.
9) Turn on generator and adjust so that speaker level input at the amplifier is
2.0V, 50 Hz
. Turn LEVEL control
full clockwise (MAX).
10) Green LED should light; immediate and vigorous bass response should be heard and felt from the port
tube opening.
Sweep Function
1) Follow steps 8-10 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 woofers and test.
Driver Function
1) Remove woofer from cabinet (instructions on exploded view drawing); and - wire clips.
2) Check DC resistance of woofer; it should be
5.7 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
5.0
V.
4) Sweep generator from 20Hz to 1kHz. Listen to driver for any rubbing, buzzing, or other unusual noises.
SUB10 Venture Series
8