If you've ever left an event thinking "the audio was rough," you're not alone. Bad event sound is depressingly common — and almost always caused by one of five specific problems. Here's how to spot them and how to fix them.
1. Cheap or misused wireless microphones
What it sounds like: dropouts, static bursts, dead spots, and that unmistakable "budget wireless" thin, phasey quality.
The fix: Digital wireless in the right frequency band. Shure SLXD, QLXD, or Sennheiser EW-DX are today's professional workhorses. Also: batteries. Fresh AA lithium batteries every event, or rechargeable systems (SB903 for SLXD) that get charged overnight. Cheap alkaline batteries don't deliver full voltage under load and cause dropouts.
2. Speakers pointed at microphones
What it sounds like: feedback — that squealing, ringing tone that erupts the moment the presenter takes a breath.
The fix: Speakers should be in front of the microphones, not behind them. Move the PA forward of the stage lip. If that's not possible, orient the speakers slightly outward (away from the mic axis). Use directional microphones (cardioid or hypercardioid). And for the love of gain — don't crank the mic to compensate for a small PA.
3. Untreated rooms with hard surfaces
What it sounds like: muddy, boomy, unintelligible speech. Bass frequencies pile up and swallow consonants.
The fix: Room acoustics matter more than most people realize. If the venue has hard floors, hard walls, and no absorption, speech intelligibility suffers no matter how good the PA is. Practical fixes include high-pass filtering the vocal channel aggressively (roll off everything below 100 Hz), narrowing the PA's coverage so you're not exciting the rear wall, and — where possible — physically damping the room with drapes or acoustic panels.
4. Wrong PA for the room size
What it sounds like: distorted, harsh sound because the PA is running at 100% just to be heard, or muddy blob-sound because it's oversized and set to 20% to avoid overwhelming the room.
The fix: Match the PA to the room. A pair of QSC K12.2 speakers cover 200 guests comfortably; scale up to line arrays only when you actually need to. If you're doing panels or fireside chats, a smaller point-source PA with careful placement will sound better than a huge system at low volume.
5. No soundcheck
What it sounds like: everything wrong at once — levels are off, EQ isn't tuned, mic gain is guessed. The first 10 minutes of the event are the soundcheck, in front of your audience.
The fix: Build 30–60 minutes into the schedule for the AV team to soundcheck with the actual presenters, on the actual gear, in the actual room. This is the single highest-impact thing you can do for audio quality — and it's free. Any AV vendor who doesn't insist on a soundcheck window is going to disappoint you.
Bonus: skimping on the FOH position
The engineer running your event needs to hear what the audience hears. If they're mixing from a back-of-house closet or behind a wall, they can't. Front of House (FOH) needs to be in the room, at ear height, roughly 2/3 back from the stage. Non-negotiable for anything that matters.
The common thread
Bad audio isn't usually a gear problem. It's a planning problem or an operator problem. Great AV vendors ask questions before the event, insist on soundcheck time, and put an experienced engineer at FOH. Cheap AV vendors show up, plug in, and hope.
Planning an event where the audio actually matters? Get a quote.
The physics of feedback (understanding it prevents it)
Feedback happens when a microphone picks up sound from a speaker, that sound gets amplified and comes back out the speaker, gets picked up again, and the loop runs away. The result is that squealing ringing tone that means the audio person has failed.
The physics are governed by three factors:
- Microphone-to-speaker distance. The closer the mic is to the speaker, the higher the risk. Placing speakers in front of the stage line moves the risk to zero at that frequency.
- Directional properties of the microphone. A cardioid microphone rejects sound from behind. A hypercardioid rejects sound from the sides. Pointing the null of the microphone directly at the speaker is a physics trick to eliminate feedback.
- Room resonance. Every room has natural resonant frequencies. Feedback usually starts at those frequencies because the room amplifies them acoustically. A trained engineer identifies the ringing frequency and pulls it down in EQ, "ringing out" the system.
Amateur audio operators usually respond to feedback by turning the mic down — which makes the presenter inaudible. The professional response is to reduce the loop gain at the specific frequency where feedback is happening, using a narrow EQ cut on the mixer.
Room acoustics 101: what you can control and what you can't
You can't easily change the fundamental acoustic properties of an event venue — the walls are where they are, the surfaces are what they are. But you can work with them.
Highly reflective rooms (glass walls, hard floors, high ceilings, minimal furniture) have long reverberation times. Speech feels smeared and unintelligible because reflections arrive at listeners after the direct sound, blurring consonants. Countermeasures: aim speakers carefully so less energy hits reflective surfaces; use narrower-coverage speakers; increase directivity; sometimes bring temporary drapes or acoustic panels.
Dead rooms (heavy carpet, drapes, acoustic ceiling, upholstered chairs) have short reverberation times. Speech is intelligible but feels distant or lifeless because the room isn't adding energy. Countermeasures: more speaker output to compensate; sometimes multiple speaker positions to keep coverage even; the sound needs to "carry itself" without room help.
Rooms that change during the event. A ballroom with 500 empty chairs sounds very different than the same ballroom with 500 warm bodies. The warm bodies absorb high frequencies more than low frequencies, making the room sound duller. Anticipate this — the soundcheck when the room is empty won't match what the audience hears once they're seated.
Outdoor spaces. No reverberation at all. Sound has to be delivered with more direct output because there's no room reinforcement. Wind is the enemy of microphones. All the indoor rules for placement and coverage still apply, just harder.