Troubleshooting; Phase Control - JBL PowerBass Series PB10 Preliminary Service Manual

Phase Control

The Phase Control determines
whether the subwoofer's
piston-like action moves in
and out in phase with the
main speakers or opposite
the main speakers. There is
no correct or incorrect
setting. Proper phase
adjustment depends on
several variables such as
subwoofer placement and
listener position. Adjust the
phase switch to maximize
T R O U B L E S H O O T I N G
If you used the high-level
(speaker) inputs and there
is no sound from any of the
speakers:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into
an active electrical outlet
and is switched on.
• Check all wires and
connections between
receiver/amplifier and
speakers. Make sure all wires
are connected. Make sure
none of the speaker wires are
frayed, cut or punctured.
• Review proper operation
of your receiver/amplifier.
bass output at the listening
position.
Remember, every system,
room and listener is different.
There are no right or wrong
settings; this switch offers the
added flexibility to adjust your
subwoofer for optimum
performance for your specific
listening conditions without
having to move your
speakers. If at some time
If there is low (or no) bass
output:
• Make sure the connections
to the left and right "Speaker
Inputs" have the correct
polarity (+ and –).
• Make sure that the
subwoofer is plugged into an
active electrical outlet and
(PB12 only) switched on.
• Adjust the crossover point.
• Flip the Phase Control
switch to the opposite
position.
• If you are using a Dolby
Digital/DTS receiver or
processor, make sure that the
subwoofer adjustments on
the receiver/processor are
set up correctly.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
in the future you happen to
rearrange your listening room
and move your speakers, you
should experiment with the
phase switch in both
positions, and leave it in
the position that maximizes
bass performance.
If you used the line-level
inputs and there is no sound
from the subwoofer:
• Check that receiver/amplifier
is on and a source is playing.
• Check that powered
subwoofer is plugged into an
active electrical outlet and is
switched on.
• Check all wires and con-
nections between receiver/
amplifier and subwoofer.
Make sure all wires are
connected. Make sure none
of the wires are frayed, cut
or punctured.
• Review proper operation of
your receiver/amplifier.
• Slowly turn the Level
Control clockwise until you
begin to hear the desired
amount of bass.
• Make sure that you have
configured your receiver/
processor so that the
subwoofer/LFE output is on.
9