PowerLite 85 Multimedia Projector

Feedback noise can occur when the microphone is too close to the projector’s speaker. To prevent feedback noise, move the microphone away from the projector’s speaker.

If you are using a wireless microphone system, the receiver’s gain (or volume) may be set too high. Lower the receiver’s gain/volume then adjust the projector’s volume. The louder the projector’s volume is set, the greater the distance you need to be away from the speaker to prevent feedback.