What is feedback? Feedback can occur as long as you have a sound system with a microphone (or instrument) and amplified speakers. It occurs when the sound from the speaker is picked up by the microphone (or instrument pickup), re-amplified, and sent through the speakers over and over again in a loop of screeches or howls.

Why does feedback occur? Technically speaking, feedback occurs when the gain is too high at the output of a microphone. Many factors can influence a feedback problem, but the layout of your system components is a major factor in persistent feedback. Proper speaker placement in relation to a microphone or instrument will eliminate most feedback problems.

Here are some common causes of feedback:

• Live microphones point in the direction of amplified speakers.
• Microphone and amplified speaker are too close
• The person holding the microphone stands in front of the speakers.
• The directional nature of the microphone: Unidirectional microphones are less likely to cause feedback than omnidirectional microphones.
• Microphones pointing at each other
• The echo caused by acoustically reflective surfaces within the room: too many echoes equals more feedback
• The presence of multiple microphones and amplified speakers – the more equipment you have, the more likely you are to accidentally create comments
• The singer holds the microphone too far away, forcing the karaoke DJ to turn up the volume on the microphone, increasing the chance of feedback.

What is the best solution for feedback? Proper setup of your team will eliminate 95% of feedback. Unfortunately, you can’t always organize your system perfectly or control the sound environment 100%. Sometimes the choice of speaker placement, especially, is non-negotiable. Therefore, the following suggestions are ideal scenario solutions, but not always possible.

• Place the speakers in front of the microphones (and instruments) or
• Point the speakers away from the person singing – 180 degrees is ideal, but not always realistic
• Do not point live microphones at each other
• Hold the microphones closer to your mouth so you can lower the volume
• Avoid cupping the microphone with your hands.
• Turn off microphones or other equipment that is not being used
• Use unidirectional microphones – An omnidirectional wireless microphone array is great, but it creates more feedback issues
• Soundproof the room: reduce the amount of echo to reduce feedback through the microphone
• If you have an equalizer, reduce the specific feedback frequency causing your problem – 400K is a common problem point