There’s nothing more annoying than microphone feedback. Whether you’re at a karaoke party, or a formal event, microphone feedback just ruins the audio quality. It can also damage your audio equipment. But luckily, there are plenty of ways to reduce or eliminate microphone feedback.
how to reduce microphone feedback
- Change the speaker placement
- Sort out the volume
- Use the microphone properly
- Use fewer microphones
- Get a feedback eliminator
- Get the acoustics right
What Causes Microphone Feedback?
Just before we jump into the 6 ways to reduce microphone feedback, we’ll run through some of the causes of microphone feedback.
Microphone feedback is produced when the signal from the microphone is amplified and is then picked up by the speaker. It creates a continuous loop which keeps getting amplified and producing the sound that we know as feedback. To prevent feedback, you need to interrupt this feedback loop.
Here are some of the common causes of feedback loops:
- Poor speaker or microphone placement
- Having the volume too high
- Holding the microphone improperly
- Poor acoustics
1. Speaker Placement
So keeping the feedback loop in mind, one of the first things you can try to reduce or eliminate feedback, is by moving the audio equipment around. The main thing you need to do, is have the microphone and speaker pointing in opposite directions. So you can do this by:
- Position the speaker in front of the singer so it’s facing the audience.
- Have the speaker and microphones as far away from each other as possible.
2. Sort the Volume Out
The second thing you can try to reduce feedback is to reduce the volume of your microphone. The higher the volume is, the higher the chance that you’ll get unpleasant feedback. This is something known as “gain before feedback”. It’s the amount of amplification that can be achieved before you get any feedback.
- Keep turning the volume of the microphone up until you start hearing feedback.
- Find the point where you have enough volume but with little feedback.
- Then mark this position on your volume control so you don’t turn it up too high when the performer is singing.
Sometimes, if the performer moves towards or away from the speaker, it’ll impact the volume you can reach until you get feedback. So try a few different positions to figure out the maximum volume you can use if the performer moves around.
If you’re dealing with a particularly difficult sound system, then it can be hard to get the volume high enough, without getting feedback. So one thing you can try and do is to reduce the competing sound. If there are any other sources of sound that are quite loud, see if you can reduce them first.
3. Use the Microphone Properly
One of the easiest ways to reduce microphone feedback, is to hold the microphone properly. If you’re a singer experiencing microphone feedback, then you can try adjusting the way you hold the microphone to avoid it. If you’re the karaoke DJ or host, then have a word with the performer and advise them how to hold the mic to avoid feedback. Here are two main things you can try.
Hold the microphone close to your mouth
If you hold the microphone too far away from your mouth, then the volume will have to be higher. This risks feedback because, as we just discussed, higher volume results in more feedback. So the closer you hold the microphone to your mouth, the less chance there is of it causing feedback.
Don’t cup the microphone
A lot of singers have developed a bad habit of cupping the microphone. This causes that classic high-pitched feedback. To avoid this, put your hand lower down the microphone so it’s away from the microphone head.
4. Use Fewer Microphones
Another thing you can do to reduce feedback, is simply to use fewer microphones. This seems obvious, but the less microphones you have, the less opportunities there are for a closed loop to form creating the horrible feedback sound. If you can’t have fewer microphones, then at least try to position them as far away from the speakers as you can. And make sure you turn any extra microphones off when they aren’t in use.
Going back to this idea of “gain before feedback”. It’s worth noting that the gain before feedback actually decreases 3dB every time the number of microphones that are on.
5. Use a Feedback Eliminator
Feedback eliminators or suppressors can also be purchased which use a few different methods of controlling feedback.
- Frequency shifting: this is an old-technique that helps increase the volume you can reach before hearing feedback.
- Notch filtering: this is an automatic control built-into some feedback eliminators and listens for feedback and then inserts a notch filter at the frequency of the feedback to block it.
- Adaptive filtering: this is used to eliminate the source of feedback from the system.
Feedback eliminators are often used by professionals to help improve the audio quality. Here are some popular feedback eliminators. Click the images to take you to the Amazon store in your region.
6. Get the Acoustics Right
Getting the acoustics of the room right, is another way to help reduce microphone feedback. The aim is to reduce the sound resonating around the room. Here’s how to do it:
- Avoid hard surfaces such as concrete, smooth ceiling or tiles.
- Use soft materials such as rugs, curtains and carpet.
- Cover large windows with curtains.
- Use foam padding over hard surfaces.
So there you go! Those are the 6 easiest ways to reduce microphone feedback.
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