8
EUROLIVE PROFESSIONAL SERIES
7. TROUBLESHOOTING
6.3 Stereo operation with a parallel stage
monitoring system and a subwoofer
This example shows the use of two B1520 PROs as FOH
loudspeakers and one B1220 PRO used as a floor monitor on
stage. The FOH loudspeakers reproduce the main stereo output
signal from the mixing console, while the stage monitor is fed an
independent monitor mix through a mono monitor send (Aux
Send). A separate subwoofer output feeds a B1800X PRO
subwoofer with the bass signal. Two stereo power amps are
required for this application, whereby one amp reproduces the
main stereo signal, and the other one reproduces both mono
signals (subwoofer and monitor signal).
Fig. 6.3: Stereo operation with a parallel stage monitoring
system and subwoofer
7. TROUBLESHOOTING
7.1 No signal when loudspeaker is connected
sMake sure that your mixing console is indeed carrying a
signal (is the master fader raised? Are channels active?)
and that the gain control on your amp is turned up.
sWhen using a crossover, make sure that the relevant
channels are active.
sCheck if the cable connection is interrupted/damaged
somewhere in your setup.
sTo test your configuration, connect another amp. If you
now get a signal, the power amp is the culprit.
sTo test your configuration, connect another speaker. If
you now get a signal, the fault lies within the speaker.
7.2 Signal present only on one channel
sMake sure that your mixing console is working properly (is
the signal present on both outputs (L/R)?).
sIf using a crossover, check if the relevant channel is active.
sCheck if the cable connection to the silent channel and to
the corresponding speakers is interrupted/damaged
somewhere along the path.
sConnect the silent loudspeaker onto the amp channel that
works properly. If you now get a signal, it is the amp channel
that is at fault. If you still can not hear anything, the fault lies
either within the loudspeaker or the cables used.
7.3 Signal distorted
sMake sure that all signals on the mixing console have been
set to optimal levels in order to avoid distortion.
sIf using a crossover, check if all signals have been set to
correct levels.
sMake sure that the power amp channels are not overdriving.
If so, turn the gain control down a little. However, it could
also be the case that your power amp doesnt have enough
power headroom, so that the required volume can not be
generated without starting to distort.
sMake sure that the level of the signal getting into the speakers
is not too high, causing distortion.
sCheck your EQ settings. Excessively increasing the
frequencies can result in distortion.
sIf distortion is still occurring despite everything you have
tried to eliminate it, try connecting a different power amp. If
you no longer hear distortion, its cause was with the power
amp.
sAs a test, connect another speaker. If you no longer hear
distortion, its cause was with the loudspeaker (perhaps a
defective loudspeaker).
sCheck if the cable connection is interrupted/defective
somewhere along the path.
7.4 Treble signal too low
sCheck the EQ settings on your mixing console or on an
external EQ, if applicable.
sMake sure that the tweeters on your loudspeakers are
positioned at the same height as the ears of the people in
the audience. If not, please modify the speaker position.
sThe internal tweeter fuse may have opened. In this case,
please contact a BEHRINGER service branch office near
you.