The Howls, Squeaks, and Roars of Audio Feedback and How to Fix It
What is audio feedback?
Feedback can seem like a difficult concept for most to understand and therefore know how to avoid, but it is actually a very simple idea and can be simple to remedy. Feedback essentially operates as an, appropriately named, feedback loop. A feedback loop, as you may remember from 7th-grade science class, is an infinite cycle where one process feeds into another, which feeds back into the first and continues forever and ever. Feedback in the world of audio is basically just a feedback loop that you hear instead of see. The howls, squeaks or roars that you hear on movies or cartoons (or even in your own sound system) is actually a particular audio frequency trapped in a feedback loop.
What causes a feedback loop?
In most cases, feedback is caused by inappropriate speaker placement. If you have speakers directly behind a microphone, sound projected into the mic emits through the speakers and is then directly picked up by the microphone, creating an endless loop of audio that amplifies it's own frequency.
How do we fix this problem?
The easiest solution is to either move the speaker to the left or right of the microphone or move the microphone away from the front of your speakers. This is why we recommend careful placement of monitor speakers and keeping speakers in front of microphones. Most setups have the speakers projecting sound from the very front of the stage, while performers are behind them. This will maximize what we call “gain before feedback,” – the loudest and clearest your system can operate without feedback.
What do you do if your microphone isn’t in front of the speaker but you're still getting those howls, squeaks, and roars?
This concept can be slightly complicated. Since feedback occurs at a particular frequency, it's possible you're experiencing higher frequency feedback because of boosting the high-frequency knob on a mixer or mixer/amplifier to enhance a system’s clarity. Introducing too many high frequencies into your space, or another frequency equalization (EQ) gain may cause feedback. In order to resolve this and reduce the chances of feedback, you may need to notch back the high-frequency equalization.
If this solution reduces the feedback but limits the high-frequency tone too much, you may need to contact us for some other more intricate solutions. A more sophisticated equalizer would literally let you notch out the specific frequency that is causing the feedback. You may also want to consider an automatic feedback destroyer or remover. These products take the guesswork out of the system tuning for you and pull out the feedback as it happens. These types of products provide a more productive and effective long-term solution.
Still have questions? Give us a call at (888) 256-4112