7
T R O U B L E S H O O T I N G
If there is no sound from
any of the speakers:
• Check that receiver/amplifier
is on and that a source is
playing.
• Review proper operation of
your receiver/amplifier.
If there is no sound coming
from one speaker:
• Check the “Balance” control
on your receiver/amplifier.
• Check all wires and connec-
tions between receiver/
amplifier and speakers.
• Make sure all wires are
connected. Make sure none of
the speaker wires are frayed,
cut or punctured.
• Make sure no wires are
touching other wires or
terminals and creating a short
circuit.
• Turn off all electronics and
switch the speaker in question
with one of the other speakers
that is working correctly. Turn
everything back on, and
determine whether the
problem is in the same place,
i.e., the speaker that was
working previously now has no
sound and the speaker that
was not working now sounds
fine; or whether it has moved,
i.e., the speaker that was not
working still has no sound and
the speaker that was working
is still fine. If the problem is in
the same place, the source of
the problem is most likely with
your receiver or amplifier, and
you should consult the owner’s
manual for that product for
further information. If the
problem has followed the
speaker, consult your dealer
for further assistance or, if that
is not possible, visit our Web
site at www.jbl.com for further
information.
If the system plays at low
volumes but shuts off as
volume is increased:
• Check all wires and connec-
tions between receiver/
amplifier and speakers.
• Make sure all wires are
connected. Make sure none of
the speaker wires are frayed,
cut or punctured.
• If more than one pair of
main speakers is being used,
check the minimum impedance
requirements of your receiver/
amplifier.
If there is no (or low) bass
output:
• Make sure the polarities
(+ and –) of the left and right
“Speaker Inputs” are
connected properly.
• Make sure that the speaker
is plugged into an active
electrical outlet and switched
on, and that the green LEDs are
displayed.
• In Dolby Digital or DTS mode,
make sure your receiver/
processor is configured so that
the subwoofer and LFE output
are enabled.
If you used the LFE input and
there is no sound from the
subwoofer:
• Check that receiver/amplifier
is on and that a source is
playing.
• Make sure that the speaker
is plugged into an active
electrical outlet and switched
on, and that the green LEDs are
displayed.
• Check all wires and connec-
tions between receiver/
amplifier and speakers.
• Make sure all wires are
connected. Review the “Line-
Level Connections” section on
page 5 of this manual and make
sure that a single RCA patch
cord is connected to each
loudspeaker from the
Y-Connector plugged into the
receiver/amplifier’s subwoofer
output. Make sure none of the
speaker wires are frayed, cut
or punctured.
• In Dolby Digital or DTS mode,
make sure your receiver/
processor is configured so that
the subwoofer and LFE output
are enabled.
If you are using the S412P
II
LFE/Subwoofer input and the
bass level decreases (instead
of increasing) when you turn
the LFE/Subwoofer Level knob
clockwise:
• Recheck to make sure that
your receiver or amplifier-
speaker outputs are correctly
connected to the S412P
II
speaker inputs (gold-plated
binding posts), (+) to (+) and (–)
to (–). The S412P
II
(+) terminal
has a red stripe and is located on
the right-hand side, below the
letter “L” of the molded JBL logo,
when looking directly at the back
of the S412P
II
.
• If the wires are connected
properly, the confusion may be
attributable to the design of your
receiver/amplifier. Your unit may
have inverting inputs, which
reverse the polarity of the signal
between the inputs and outputs
of the amplifier. To check if this is
the case, reverse the speaker
connections for
ALL
S412P
II
’s in
your system (and disconnect any
other speakers in the system)
so that the receiver/amplifier’s
(+) connector is connected to
each S412P
II
’s (–) (black stripe)
speaker connector. If you do
this and the S412P
II
’s function
properly (bass increases as you
turn your LFE/Subwoofer level-
control knobs clockwise), your
receiver/amp uses inverting
inputs. This is not a problem.
Simply connect all of the
speakers in your system the
same way, with the receiver or
amplifier’s (+) terminal to the
speaker’s (–) terminal, and the
receiver or amplifier’s (–)
terminal to the speaker’s (+)
terminal.
