Eliminating Feedback

Feedback is the classic sound nightmare — and it’s simple to understand. A mic feeds the console, which amplifies it out the speakers; if that amplified sound gets back into the mic, the loop runs away — mic → PA → mic → louder → that awful screaming feedback loop. Floor monitors are especially prone, since there’s a speaker pointed right at the mic.

Preventing feedback

• Watch your levels. You can’t endlessly turn up a soft singer’s monitor — past a point it will feed back. Sometimes there has to be a reality check: “that’s about as much as I can give you.”
• Keep monitors minimal. Only put in a wedge what that person actually needs (drummer next to the kit doesn’t need drums). Less in the wedge = less feedback.
• Mic placement vs. the monitor. Learn your mics’ polar patterns (how narrowly/broadly they pick up) and place the wedge in the mic’s rejection zone — sometimes slightly off to the side, since even tight patterns pick up a little from behind.
• Don’t get too far forward. A mic directly under the PA can catch bleed off the top; and stepping out in front of the PA is an almost guaranteed feedback recipe.
• Go as un-mic’d as possible. Only open mics feed back — there’s nothing to loop on a keyboard or a DI. Amp-modeler instead of mic’d cab, digital keyboard instead of mic’d piano, bass direct, fewer wedges, less in the wedges. (Caveat: acoustic guitars with piezo pickups can feed back — the pickup acts like a mic.)

Identifying the culprit

Don’t just yank the master fader in a panic. Ideally catch it at soundcheck: pause, and have the engineer boost mics one at a time to find which is the source (it might surprise you — an acoustic’s pickup, a pulled-back choir mic). There’s nothing worse than fighting feedback for 20–30 minutes — pause, let the sound tech find it, then move on.

Remember it’s only ever open mics. And sometimes the answer is “a little of everything” — several vocal mics each sitting on the edge collectively tip into feedback. The fix may be pulling the whole group down a touch rather than hunting one channel.

Killing the ringing frequency (EQ as defense)

EQ isn’t only for tone — it’s a feedback weapon. Feedback rings at a specific frequency, so find it and dip it:

1. Have the singer stop so you can hear the mic sit right on the edge of ringing.
2. Boost and sweep (carefully — don’t let it scream) until you find the ringing frequency.
3. Cut it narrow. This EQ move is defense, not tone — a tight cut buys back just enough headroom. (Alternatively, set an extreme cut and sweep until the ring stops.)

This is the same boost-sweep-cut technique as tonal EQ, just aimed at the feedback frequency. Pulled-back choir mics are a common offender (turned up loud to cover distance) — high-pass off what you don’t need and ring out the problem frequencies.

Worship leaders can help: if you can match and hum the feedback tone, lean into it so the engineer can find and pull it faster.

One caveat on the master fader

Pulling the main fader only fixes feedback that’s in the PA — if it’s in someone’s monitor, it’ll keep ringing. Go to the actual source.

The “more war” — and how to end it

Don’t solve monitor complaints by adding (“I need more of me” → “now I need more drums” → endless). Instead, take away what they don’t need — just like cutting problem EQ frequencies before boosting. Turn the unneeded things down and what they want to hear stands out clearly, with no extra level (and less feedback risk).

Application

• Walk your stage: which sources could go direct/modeled to remove an open mic from the equation?
• At your next soundcheck, practice ringing out a vocal mic — boost, sweep, narrow-cut the feedback frequency.
• Next time someone wants “more,” try taking something else out of their monitor instead.