Feedback from the system

Move the microphone or instrument away from the speaker.
The microphone or instrument (typically an acoustic guitar) may be too close to the speaker. Do not stand directly in front of the speaker or point the mic or instrument towards it.

Have the vocalist/announcer move closer to the microphone.
Proper mic technique is essential. Keeping a microphone between 0.5 and 1 inch away from your mouth will help to capture the full tone of your voice, therefore relieving the need to boost the mic enough to hear it. As you sing considerably louder, move the mic away slightly or move your head a little to the right or left. As you reduce your dynamics, move back to your usual position.

Make sure the levels have been set properly.
If the levels are not set properly, performance will suffer. Follow these guidelines when setting levels:

1. Check the signal LED to make sure the input trim level is sufficiently high. The LED should be solid green, indicating a strong signal
2. If the LED is not solid green, increase the input trim level, stopping before the LED is red.
3. When the input trim level is correct, increase the channel volume and master volume to the desired levels.
   

Make sure the correct ToneMatch preset has been selected.
An incorrect preset can affect sound quality. If there is no exact preset for the microphone or instrument, set the control to "Flat." .

Make sure no unwanted processing has been applied.
Disable any unwanted reverb, delay, compression, gating, EQ effects (zEQ and Parametric EQ) or all effects (FX mute on affected channel).