JBL HTPS-400 - Manual (Page 7)

T R O U B L E S H O O T I N G
The Phase switch is used to
adjust the relative polarity of
the subwoofer to the other
speakers. When the speakers
are out of phase, the low-
frequency sound waves will
cancel each other out,
reducing bass response.
The HTPS-400 provides a
convenient phase switch that
allows you to remedy this
situation without relocating
the speakers or changing any
speaker connections. In normal THX operation, the
Phase switch should be set to
0 degrees so that the sub-
woofer is operating in phase
with the main speakers. This
should produce a smooth
frequency response up to
80Hz. In rare cases when the
subwoofer is placed more
than 25 feet away from the
main speakers, or where the
subwoofer is not being used
with a THX-certified receiver,
or processor, and speakers, the 180-degree position may
provide a smoother frequency
response.
Listen to your HTPS-400
subwoofer and main speakers
with the switch in the “0°”
position, then listen to the
same material with the switch
set to “180°”. Decide which
sounds better and leave the
switch in this position. Repeat
this procedure if you change
the location of the subwoofer.
Phase
If there is no output from the
subwoofer:
• Make sure the system is on
and a source is playing.
• Make sure the HTPS-400 is
plugged into an active outlet
and the power switch is in
either the “Auto” or “On”
position.
• If you are using a THX-
certified processor/receiver,
make sure the THX/Normal
switch is set to “THX.”
• If you are not using a THX-
certified processor/receiver,
make sure the THX/Normal
switch is set to “Normal.”
• Adjust the “Output Level”
(Gain) control.
• Review proper operation of
your receiver/amplifier.
• Check all wires and make
sure they are properly
connected. Make sure none
of the wires are frayed, cut or
punctured.
• If you are not using a THX-
certified processor/receiver,
make sure that you have
configured your processor/
receiver so that the subwoofer/
LFE output is on.
If there is no (or low) bass
output:
• Make sure that the sub-
woofer is plugged into a live
electrical outlet and the
power switch is in either the
“Auto” or “On” position.
• Adjust the “Crossover
Frequency.”
• Adjust the “Output Level”
(Gain) control.
• Change the setting on the
Phase switch.
• If you are not using a THX-
certified processor/receiver,
make sure that you have
configured your processor/
receiver so that the sub-
woofer/LFE output is on.
If you are hearing midrange
frequencies (such as vocals)
through the subwoofer:
• When using the THX mode,
make sure the subwoofer
crossover is activated on your
processor/receiver.
• When using the Normal
Mode, adjust the “Crossover
Frequency” to a lower
frequency.
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