QSC CMXa Série Mode D'emploi page 18

Problem: No channel separation
Check the switch settings on the back of the amplifi er. Make sure the "Parallel Input" and "Bridge Mode" switches are OFF in dual-channel, bi-amp, or
stereo use where different signals go to each channel.
Make sure other equipment in the signal path, such as mixers, preamps, etc., are set for stereo, not mono.
Problem: Hum
Move cabling and signal sources to identify "hot spots" in the system. Cables with faulty shielding are a frequent entry point for hum.
Problem: Hiss
Unplug the amplifi er input to confi rm that the hiss is coming from the source or a device upstream; erratic or popping noises indicate an electronic
fault in the offending unit.
To keep the normal noise fl oor low, operate the primary signal source at full level, without clipping, and avoid boosting the signal further between the
source and the amplifi er.
Problem: Squeals and feedback
EN
Microphone feedback should be controlled with mixer controls. If noise continues to build up with zero mic gain, there is a serious fault in the signal
processors or cables. Working in succession from the signal source towards the amplifi er, check each device in the signal path by reducing its gain or
unplugging it.
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