Feedback is the ultimate enemy of every sound producer, DJ and announcer.  It’s that annoying squeal that hurts your ears and can do some serious damage to sound systems, avoiding it is very important.  There are feedback filters, limiters, gates, and all kinds of other cool gadgetry that helps to prevent it, but it happens when the microphone catches the signal from the sound system.  Since different sounds travel at different speeds (frequencies), knowing and understanding a few basic concepts will help you keep feedback from happening.

The first is how you hold the microphone.  If you hold a microphone straight up, you’re asking for feedback.  The microphone is searching for signal the the closest signal will be from the sound system, so don’t hold the microphone straight up.

The second is how loud you turn up your microphone.  To create feedback.  Don’t do this next sentence: Turn the mic and master volume all the way up, then turn the mic on.  Now that you’re deaf you don’t have to worry about feedback anymore (please don’t do this).  Since you were smart enough not to do the above, you now understand that the microphone is grabbing the sound.  Sound systems even put out frequencies that you can’t hear but the microphone can still pick up which is why you get feedback even though it sounds absolutely quiet.

The third is how loud you have your microphone, your music and the sound system.  There have been times the music is causing the feedback, and most of the time it will be a low feedback sound when it’s the music.  If it’s a high-pitched sound, then it’s the microphone.  Very important to understand this.

To combat feedback without all of the technology that’s available you can do some simple things:

1. Turn down the master volume
2. Turn down the music volume
3. Turn down the microphone volume

But if it’s too quiet, there are some things that you can do to help you with the sound.  You would think that since you have a high-pitched feedback, you would scale back (turn down) the highs.  Yes, but you can also take out too much and the person speaking becomes hard to understand.  So you would turn down the mid-level frequencies, but you have the same problem.  Now what?

Return your highs and mids to their levels, but also increase some of the lows.  The low level frequencies will help to “muddy” the highs and mids and slow down their speed which will help to stop the feedback.  This allows you to grab some extra volume as well, but you’re also dancing a fine line between feedback and a clear signal.  A little practice and experimenting will get you to where you want to be.  You may need to still scale back the mids and highs but you won’t lose the quality.