What is feedback?
We have all heard that loud pitched squeaking/howling noise coming from the speakers during a presentation. Sometimes it is unbearably loud, sometimes it is unreasonably frequent, but every time it is annoying and unprofessional. This phenomenon in professional sound equipment is commonly referred to as feedback.
How does feedback occur?
Feedback occurs when the microphone is placed in a bad spot in relation to the speakers. When the mic is in front of the speakers, the noise from the speakers travel back through the microphone and then out the speakers even louder, repeating as fast as the speed of sound until you hear the high pitched squeak.
Some advanced soundboards include an anti-feedback button that will cut feedback out and cause those sound levels to be brought back to a reasonable level. Another common error is when a person with a wireless lapel mic steps up to a lectern and speaks into the microphone and also through the lapel mic. This can be a cause of feedback because the mics are too close to each other. PoP voice Professional Lavalier Lapel Microphone B016C4ZG74
How do you avoid feedback?
1. Placement of the mic. Place the microphone at least ten feet from the speakers and never right in front of the speakers.
2. Optimize the placement of the speakers. Speakers should be placed in a way to cover the most area but not blow people away with sound. Leave 10-15 feet in between where people will be sitting and the speaker system.
3. Teach microphone users how feedback works. I encourage you to pull up this video on microphone feedback on your smart phone to help communicate how feedback works.
4. Test system adequately before presentations. It is recommended to test each specific device you will use (such as a CD, iPod, projector, etc.) and make sure everything is working properly. This is a principle in being prepared for presentations so Murphy doesn’t make an appearance (Murphy’s Law is “anything that can go wrong, will.”).