3 Tips to Stop Audio Feedback
Feedback from the sound system is one of the most annoying distractions from the sound system.
As a new volunteer sound tech, feedback was my arch nemesis! A successful service was defined by the simple test of whether there was feedback in the middle of service or not. The interesting thing was that as I became more experienced, it was clear that feedback wasn’t my real problem. It was the result of a problem I had failed to address!
Feedback is not the problem. It is a result of a problem that needs to be fixed.
Fortunately the audio issues that cause feedback can absolutely be fixed, sometimes rather quickly. Stopping feedback often comes down to three primary issues: volume, mic location, and EQ.
Tip #1. Turn it down!
Ok, yeah. This one seems pretty obvious. But hold on a minute. You might not have to turn things down as much as you think.
Sometimes you may only need to turn down the stage monitors a little bit to stop the ringing. Or try bringing down the offending microphone channel fader just a couple dB. A small change in the overall acoustic energy in the room can be enough to take the sound quality from “crisis mode” to at least bearable.That faint ringing you hear in the loudspeakers? That’s a microphone getting ready to feedback. Turning it down a little bit can often get rid of the ringing. But turning it down is probably not the best solution. If you have the option, you really should try…
Tip #2. Move it!
The most important thing you can do to improve your sound quality and reduce the risk of feedback is to place your microphones close to the source you are trying to reinforce.
If you have problems with feedback, move the mic closer to the source. Vocal mics should be held or placed within 1-2” of the mouth. Clip-on lavaliere mics should be placed within 6-8” of the chin. Headset mics should generally rest just above and back from the corner of the mouth. Choir mics and overhead mics for instruments may present some additional challenges. If you struggle with feedback from these mics, be sure to eliminate their feedback from any nearby stage monitors.
And pay attention to the microphone pickup (or polar) pattern. This defines how wide or narrow the pickup field is around the mic. You may want to use a narrow pickup pattern like super-cardioid to eliminate extra noise from the sides of the microphone. When all that just isn’t cutting it…
Tip #3. EQ it!
The precision use of EQ can be highly effective in eliminating feedback. You don’t have to get fancy either. Even a sweepable mid EQ on an analog console is a powerful tool for stopping most common feedback frequencies. Interestingly enough, feedback often occurs at lower frequencies than you might suspect.
Try this trick: Select your EQ filter and make a -6dB cut on the level or gain control for that filter. Then take your parametric EQ or sweepable mid EQ frequency knob and sweep the frequency spectrum to listen for where the ringing diminishes or stops altogether. This is one of the fastest ways to stop feedback if it ever happens during a live worship service or event. Sure, these may seem like simple tips, but they can make a big difference as you practice using them. You don’t need to be afraid of feedback. Take a proactive approach to fixing the underlying problems and you can banish feedback from your worship service.
If you’d like more details about how you can stop feedback and other common worship distractions, you can download my free guide about it
here.
Author / Audio Engineer
Great Church Sound | Missoula, MT
greatchurchsound.com
James Wasem has been fascinated by sound and electricity from an early age. His love of music and technical gear made sound engineering and systems integration a natural pursuit. James has spent the last 20 years performing and touring in bands as a drummer, mixing live sound for churches, schools and theatres, and working as an audio systems installer and designer.
Though involved in highly technical fields, James has a passion for making things simple to understand and easy to use. It was from this passion that the book Great Church Sound – a guide for the volunteer was born. James believes that technical ministry volunteers provide a critical service for their congregations and should be well equipped with quality tools to help them grow in craft, skill, and spirit.
James and his wife Kate (who also provided the illustrations for Great Church Sound) live in the beautiful Rocky Mountains of Missoula, Montana.
