Cd vs. microphone

A few possibilites.

1. Even though you have some kind of peak limiting on your mics, the signal might still be peaking somewhere along the audio path and causing distortion. Gain controls might be set too high somewhere along the way.

2. The amp you are using might simply be driving too much power for the speakers to handle.

3. A faulty connection, connector, wire or input could cause distortion of something like distortion which is of course would be more apparent at higher volumes.

4. Equipment placement could be picking up sounds or interference from other sources.

5. If you are able to discern level peaks but they are occasional and not flat out, then a compressor placed in the mic signal path could certainly help - otherwise see # 1 above.

Best of luck in solving this.

Cheers.

bd.