Mackie SRM550 Owner's Manual - Poor Bass Performance
SRM550 • SRM650 • SRM750 P
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SRM550 • SRM650 • SRM750 Powered Loudspeakers
Appendix A: Service Information
Poor bass performance
• Check the polarity of the connections between the
mixer and the loudspeakers. You may have your
positive and negative connections reversed at one
end of one cable, causing one loudspeaker to be
out-of-phase with the other.
• Poor bass performance may be the result of bad
AC power. See the section titled ‘AC Power’ on
page 13 for further details.
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 connections are secure.
Noise
• What is the position of the gain knob? It should
be at (or near) “mic” when a mic is connected
and at (or near) “line” when a line-level signal
is connected. It should be “off” for all unused
inputs.
• 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 transformers, or other
EMI-inducing devices.
• Is there a light dimmer or other SCR-based device
on the same AC circuit as the SRM loudspeaker?
Use an AC line filter or plug the loudspeaker into
a different AC circuit.
If you think the SRM loudspeaker has a problem,
please check out the following troubleshooting tips and
do your best to confirm the problem. Visit the Support
section of our website (www.720trees.com) where you
will find lots of useful information such as FAQs and
other documentation. You may find the answer to the
problem without having to part with your loudspeaker.
Troubleshooting
No power
• Our favorite question: Is it plugged in? Make sure
the AC outlet is live [check with a tester or lamp].
• Our next favorite question: Is the power switch
on? If not, try turning it on.
• Is the Running Man logo on the front panel
illuminated? If not, make sure the AC outlet
is live. If so, refer to “No sound” below.
• The internal AC line fuse may be blown. This is
not a user serviceable part. If you suspect the
AC line fuse is blown, please see the "Repair"
section next.
No sound
• Is the input gain knob for the input source
turned all the way down? Verify that all the gain
knobs in the system are properly adjusted. Look
at the level meter to ensure that the mixer is
receiving a signal.
• Is the signal source working? Make sure the
connecting cables are in good repair and securely
connected at both ends. Make sure the output
level control on the mixing console is turned up
sufficiently to drive the inputs of the speaker.
• Make sure the mixer does not have a mute on or a
processor loop engaged. If you find something like
this, make sure the level is turned down before
disengaging the offending switch.
• Has it shut down? Make sure there is at least
six inches of free space behind each SRM
loudspeaker.