Mackie DLM12 Owner's Manual

Owner’

s Manual

•  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
   the previous page for further details.

•  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.

•  What is the position of the mic / line switch?

    It should be IN when a mic is connected and
    OUT when a line-level signal is connected to
    the channel 1 input.

•  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 DLM8/12? Use an
   AC line filter or plug the loudspeaker into a  
   different AC circuit.

•  Try disconnecting the cable connected to the main

   input jack. If the noise disappears, it could be
   a “ground loop,” rather than a problem with the
   DLM loudspeaker. Try some of the following  
   troubleshooting ideas:

•  Use balanced connections throughout your system

   for the best noise rejection.

•  Whenever possible, plug all the audio equipment’s

   line cords into outlets which share a common
   ground. The distance between the outlets and the
   common ground should be as short as possible.

If you think your Mackie product 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.mackie.com/support)
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 send your Mackie
product away.

•  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 power LED on the front panel glowing

   green? 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.

•  Is the input level control for the input source

   turned all the way down? Verify that all the level
   controls 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 DLM

   loudspeaker.