No sound

Is the input LEVEL control for the input source or the subwoofer turned all the way down? Verify that all the volume controls in the system are properly adjusted.

Is the signal source working (and making union scale)? Make sure the connecting cables are in good repair and securely connected at both ends. Make sure the output volume (gain) 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 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 SWA1501.

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 loud- speaker 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 SWA1501 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 com- pletely into the jack? Be sure all connections are secure. It’s a good idea to periodically clean all electrical connections 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 SWA1501? Use an AC line filter or plug the SWA1501 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 SWA1501. 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 linecords into outlets which share a common ground. The distance between the outlets and the common ground should be as short as possible.

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