Mackie SWA2801z Speaker User Manual


 
8
Make sure the mixer does not have a
Mute on or a Processor loop engaged. If
you find something like this, make sure
the volume/gain is turned down before
disengaging the offending switch.
Is the thermal protection circuit activated?
Make sure there is at least six inches of
free space behind the SWA2801z.
Poor bass performance
Check the polarity of the connections
between the mixer and the loudspeak-
ers. You may have your positive and
negative connections reversed at one
end of one cable, causing one loudspeak-
er to be out-of-phase.
Try switching the
PHASE switch on
the rear panel. This affects the polarity
between the full-range speakers and the
SWA2801z and may improve the low-
frequency response.
Poor sound
Is it loud and distorted? Make sure that
you’re not overdriving a stage in the
signal chain. Verify that all level controls
are set properly.
Is the input connector plugged
completely into the jack? Be sure all con-
nections are secure. It’s a good idea to
periodically clean all electrical connec-
tions with a non-lubricating electrical
contact cleaner.
Noise
Make sure all connections to the active
loudspeakers are good and sound.
Make sure none of the signal cables are
routed near AC cables, power trans-
formers, or other EMI-inducing devices.
Is there a light dimmer or other SCR-
based device on the same AC circuit as
the SWA2801z? Use an AC line filter or
plug the SWA2801z into a different AC
circuit.
Hum
Try disconnecting the cable connected
to the INPUT jack. If the noise disap-
pears, it could be a “ground loop,” rather
than a problem with the SWA2801z.
Try some of the following troubleshoot-
ing ideas:
Use balanced connections throughout
your system for the best noise rejection.
Whenever possible, plug all the audio
equipment’s linecords into outlets which
share a common ground. The distance
between the outlets and the common
ground should be as short as possible.