Tips for reducing feedback when using a microphone with a speaker, amplifier or PA

1 1 1 1 1 Rating 3.50 (4 Votes)

microphoneFeedback is possible any time you have a microphone that is amplified by a speaker or PA system. We've put together some common steps that should be taken with any system, large or small, to reduce the likelihood of feedback.  These tips apply to small karaoke setups or large stage venues alike and are the first measures you should take to reduce feedback in your setup.

What causes feedback, and how can I prevent it?

Feedback can occur any time a microphone can hear 'itself' being amplified by the speaker. So, to avoid feedback, you need to prevent the mic from hearing itself. To do this, you need to minimize the amount of amplified that is sound coming out of the speaker and going back into the microphone.

To help visualize this...imagine that the head of the mic, and the face of the speaker both have eyeballs. If they can see each other, you're probably going to get feedback.

 

Avoid this common setup mistake

Don't position the speaker behind the performer (with the mic) pointing at the back of the performer's head. This arrangement has the speaker and mic 'looking' directly at each other. This won't work with any system and is a recipe for a bad time.

 

To prevent feedback...

  1. Improve the placement of the performer (with the mic) relative to the speaker.

    Perform either of the following:

    1. Position the speaker in front of the performer pointed at the audience. This arrangement has the mic and the speaker 'looking' in the OPPOSITE direction, AWAY from each other. This arrangement is the most resistant to feedback, and makes the most sense for karaoke.

      or...

    2. Position the speaker in front of the performer, pointing at the performer. This arrangement has the mic and the speaker 'looking' in the SAME direction, and the mic is not pointed at the speaker. This arrangement is less resistant to feedback than 1a above. It will allow the performer to hear themselves the best, but the audience won't be able to hear as well.

  2. Get the volume setting just right.

    Feedback is more likely at higher volumes because the sound is able to spill around corners from the speaker into the microphone.

    Once you've improved placement of the performer (with the mic) and the speaker, adjust the volume UP until feedback starts to occur, then turn it DOWN, to a little bit below the level where feedback starts to occur. Find the setting where you get the maximum volume possible without feedback. Keep in mind if the performer moves to a different position, the sound reaching the mic will change, and feedback could occur. Because of this, set the volume just a bit lower than you think you should to give yourself a little safety margin.

 

How can both the performer and audience hear the performance?

If you only have one speaker, it should be pointed at the audience, and the performer (with the mic) needs to be behind the speaker as described in 1A above.   

If the performer also needs amplification to hear themselves, and the setup described in 1A above doesn't get enough volume to the performer. A second speaker will be needed in addition to the main speaker to allow the performer to 'monitor' themselves.  A monitor setup can be achieved with either a second speaker positioned as described in 1B above, or can be achieved with headphones.

 

Popular

Latest Articles