A Layman's Guide to Audio Feedback: What it is and how to fix it.

Understanding and Preventing Audio Feedback. Audio feedback is one of the most common (and preventable) frustrations in live church sound. What Is feedback? Feedback happens when sound from the loudspeakers is picked up by a microphone, sent back through the mixer and amplifiers, and out the speakers again—creating a self-reinforcing loop. Certain frequencies build up rapidly until they explode as a loud squeal or howl. It’s physics, not magic, and it almost always points to a gain or placement issue in the signal path.

Most Common Feedback Causes in Worship Settings

Churches are especially prone to feedback because of:

1. Microphone placement and technique — Mics too far from the mouth (or sound source), pointed toward speakers/monitors, or held incorrectly.

2. High stage volume — Loud floor wedges or side fills that bleed into open mics (especially choir, acoustic guitar, or lavalier mics).

3. Gain structure problems — Input gain set too high, forcing the system to work harder and ring (feedback) sooner.

4. Room acoustics — Hard surfaces, high ceilings, and reflections that bounce sound back into microphones.

5. Too many open mics — Multiple live channels (choir, band, pastors) increases the chance of pickup.

6. Poor speaker positioning — Main speakers or monitors aimed such that their output is directed into the mic pickup pattern. Lavalier and lectern mics are frequent culprits because they are positioned further from the mouth than a handheld or headset mic.

   
   

Best Practices for Installation, Setup & Tuning

1. Fix physical placement first (this gives the biggest improvement)

   Position main speakers in front of the performance area, elevated and angled down toward the congregation so they don’t fire directly back at open mics. For stage monitors, place wedges behind the microphone’s null point (the rejection side of the cardioid pattern, which is the back of most stage mics). Better yet, move to in-ear monitors when possible—they dramatically lower stage volume and feedback risk.

   

2. Get mics close to the source

   Encourage vocalists and speakers to keep handheld mics 1–3 inches from the mouth. Switch lavalier or lapel mics to headsets or handhelds whenever practical—closer mics deliver far more gain before feedback.

3. Set solid gain structure

   Gain-stage correctly: strong, clean signal at the preamp without clipping, then use faders for mixing. Avoid the temptation to “turn it up at the mic” to solve volume issues.

4. Ring out the system properly

   This is an "only if necessary" suggestion as it involves actually changing the frequency range of the source. Do this at actual performance volume with all relevant mics open. Slowly raise the master until you hear the first hint of ringing, then use parametric or graphic EQ to gently notch the offending frequency (usually 2–3 dB cuts). Work through the problem frequencies one at a time. Many teams also bus vocals or choir mics together and EQ the group for efficiency. Add low-pass filters on vocal channels to reduce low-end buildup that can contribute to rumble or feedback.

5. Consider simple tools Feedback eliminators (automatic notch filters) or basic DSP, while improving by the moment, may be useful in extreme cases on a system that’s already well-placed and gain-staged.

Check out the following for additional exposition and demonstration of the above:

https://www.youtube.com/watch?v=X0sf2ZuQKGM

Pointers to Address Feedback During the Service or Performance

• Soundcheck at show volume — Have everyone speak and sing at performance level. Walk the stage with mics to catch hot spots.

• Mute what isn’t in use — Close channels or use automix/gating features. Fewer open mics = less chance of feedback. Consult your friendly AVE sales guy for products and methods to accomplish this.

• Train quick response — Teach your team to identify the offending mic quickly (by ear or solo) and either pull the fader slightly or apply a fast EQ cut. Feedback often starts as a subtle ring before it screams.

• Train— Teach worship leaders and pastors: Where and postion your headset and lavaliers correctly and consistently. Avoid turning mics toward speakers, and move deliberately on stage.

• Stay proactive — Have someone actively listening and make small adjustments in real time rather than waiting for a problem appear.

Final Encouragement

The best defense against feedback is prevention through good physical setup, proper mic technique, and disciplined gain structure. EQ and processors are helpful tools, but they can’t fully overcome poor placement or excessive stage volume. With a little training and consistent habits, your team can keep the focus on worship instead of chasing squeals. Your congregation (and your ears) will thank you.