Why is my microphone giving me feedback?

Feedback happens when sound from the speakers gets back into the microphone and loops. The usual cause is the microphone standing in front of the speakers, or the gain being pushed higher than the room needs. Move the microphone behind the speakers, aim the speakers away from it, and get the mic closer to the mouth so you need less volume. Read the full feedback section.

Why should I use a lapel microphone instead of a handheld?

A lapel, or lavalier, frees up both hands and works well for a presenter who moves, demos something, or will not reliably hold a microphone up. The trade off is that it sits further from the mouth and hears in every direction, so it feeds back sooner and picks up more room noise. See where a lavalier goes.

Where exactly do I clip a lavalier microphone?

High on the center of the chest, about a hand width below the chin, clear of necklaces, lapel pins, beards and scarves. Clipped too low, the voice goes thin and quiet. See the placement diagram.

What is the difference between gain and volume?

Gain is how loud the signal goes into the mixer. Volume is how loud it comes back out of the speakers. Distortion is a gain problem, and turning the volume down will not fix it. Read the gain versus volume section.

How far should I hold a microphone from my mouth?

Two to four inches. Closer than that and it gets boomy, further and you lose volume and invite feedback. Keep your hand off the top grille and off the bottom of a wireless handheld, because the bottom is the antenna. See how to hold a mic.

Can I put two speakers next to each other?

You can, but you should not want to. Two speakers side by side create loud spots and dead spots where their sound waves add and cancel. Spread them apart, or angle them away from each other. See why side by side speakers cause problems.

Why can nobody hear at the back of the room?

Usually the speakers are too low, aimed wrong, or too few for the width of the room. Speakers on the floor get absorbed by the first few rows of people. Get them up on stands or flown, and check the splay angle for your model. Read about speaker splay.

What is a line array and do I need one?

A line array is a set of small speakers engineered to act as one controlled beam, so the level stays even from the front row to the back wall. You need one when the room or crowd is bigger than a pair of speakers on sticks can honestly cover. Compare speaker types.

What is a column array speaker used for?

A tall, narrow speaker that throws sound out across the room instead of at the ceiling and the floor. They work well in rooms with hard walls, high ceilings and a lot of glass, where a normal speaker would just make echo. Read about column arrays.

Is it bad to blow into a microphone to test it?

Yes. Blowing into a microphone can damage the capsule that picks up sound and shortens the life of the mic. Say “check, check” instead. See our microphone handling rules.

My microphone is completely dead. What do I check first?

Power, then battery, then the mute switch on the body of the microphone. That order solves it the large majority of the time before you touch anything on the console. See the full troubleshooting list.

Do I need to hire an audio team or can I rent the gear?

Both are options. If the room is small and you have two or three microphones at most, renting is often the right call, and our prices are published. If it is a keynote, an awards night, a livestream, or a room bigger than a pair of speakers can cover, hire the crew. Read when to bring in a team.

Event Audio 101 | Mics, Feedback and Speaker Placement

We get asked by potential customers all the time why the companies they hire get feedback all the time. So to make it easy, we put together this guide. Simplified, so you can understand how you might be able to fix your feedback problem.

We run corporate AV, live sound and staging across the Wasatch Front and the mountain towns, and we rent out the same gear we use ourselves. Whether you hire an audio team or run the system yourself, the rules below are the same.

The sound chain: four steps, every single time

Every sound system is the same four steps in a row. A person talks. A microphone hears it. A mixer decides how loud it is. Speakers push it out to the room. That is the whole thing.

Event audio signal chain diagram showing source, microphone, mixer and speakers in order — The audio chain runs source to microphone to mixer to speakers. When something sounds wrong at an event, the problem is sitting on one of these four links.

This matters because it tells you where to look when something goes wrong. If the room cannot hear the speaker, the fault is on one of those four links. Start at the front and work backward.

Four things worth learning

Reeverb Entertainment slide listing four event audio basics: mic handling, gain, feedback, speaker placement — The four skills that fix most event sound problems: how to hold a mic, gain versus volume, stopping feedback, and where to put speakers.

Learn these four and you have covered the vast majority of what goes wrong at a wedding reception, a corporate general session, a school assembly or a fundraiser.

How to hold a handheld microphone

The single biggest jump in sound quality at any event is free. It is just holding the microphone correctly.

How to hold a handheld wireless microphone correctly, showing the two to four inch distance from the mouth — Hold a handheld microphone two to four inches from your mouth, keep your hand off the top grille, and never grip the bottom of a wireless handheld because that is the antenna.

Hold it two to four inches from your mouth, not down by your chest.
Do not cup your hand over the top. Cupping the grille kills the microphone pattern and invites feedback.
Never drop it. A dropped capsule is usually a dead capsule.
On a wireless handheld, keep your hand off the bottom. That is the antenna, and covering it is what causes the crackle and dropout people blame on the sound company.

If a presenter will not keep the microphone up, that is usually the moment we move them to a lavalier. We break down that decision in our guide to handheld versus lavalier microphones for conferences.

Where a lavalier microphone actually goes

Correct lavalier microphone placement high on the center of the chest on a presenter in a suit — Clip a lavalier high on the center of the chest and keep it clear of jewelry, beards and scarves, which are the three things that turn a clean lav into a rustling mess.

A lavalier lives high on the center of the chest, roughly a hand width below the chin. Too low and the voice goes thin and quiet, because you are pointing the microphone at a shirt instead of a mouth.

Keep it away from necklaces and lapel pins. Metal on metal is a tapping sound the room will hear all night.
Keep it clear of beards and scarves. Anything that brushes the capsule makes noise.
Lavaliers hear in every direction, which is exactly why they feed back sooner than a handheld does.

One rule for every microphone: never blow into it to test it. Say “check, check” instead. Blowing damages the part inside that picks up sound.

Pickup patterns: point it at what you want to hear

Microphone pickup pattern comparison chart showing cardioid, super cardioid and omnidirectional coverage — A cardioid microphone hears mostly what is in front of it, a super cardioid hears an even narrower slice, and an omnidirectional lavalier hears everything from every direction.

Every microphone has a shape it listens in. A cardioid hears mostly what is directly in front of it and rejects what is behind. A super cardioid narrows that even further, which is great for blocking out wind or traffic but only works with someone who will keep the microphone close. An omnidirectional lavalier hears everything from all directions, and that is exactly why lavs feed back more often than handhelds.

Gain versus volume, and why they are not the same

Audio mixer showing the gain knob, channel volume fader and master volume control labeled — Gain sets how loud the sound goes into the mixer. Channel volume and master volume set how loud it comes back out of the speakers. They are not the same control.

Gain is how loud the sound goes in. Set it too high and the audio sounds scratchy and crunchy, like a broken speaker. Set it too low and you get a hissy, thin voice that nobody can make out.

Volume is how loud the sound comes out of the speakers. If a microphone sounds distorted, turning down the volume will not fix it. The damage already happened at the gain stage.

Why microphones squeal, and how to stop it

Diagram showing feedback prevention by keeping microphones behind the speakers at an event — Feedback prevention comes down to geometry: keep microphones behind the speakers, aim speakers away from the mics, and run the mics only as loud as the room actually needs.

Feedback is the squeal everybody recognizes and nobody can explain. Here is the explanation: sound leaves the speaker, gets picked up by the microphone, goes back through the system, comes out of the speaker again, and gets picked up again. The loop repeats so fast that it stacks up into that howl.

Illustration of how microphone feedback happens when a mic stands in front of the speakers — Feedback starts the moment a live microphone stands in front of the speakers. Sound goes into a loop, like two mirrors facing each other, but with sound instead of light.

Keep microphones behind the speakers, never in front of them.
Aim the speakers out at the audience and away from where people will be talking.
Run the microphone only as loud as the room needs. Every extra decibel of gain brings you closer to the squeal.
Get the microphone closer to the mouth. Close mic technique buys you more usable volume than any knob on the console.

Where the speakers go

Speaker placement is where most self run systems quietly fall apart. The gear is fine. The positions are not.

Diagram showing why two speakers placed side by side create loud and quiet spots in a room — Two speakers pushed side by side fight each other. Where their waves line up the sound gets louder, and where they collide it drops out, so the room ends up with loud spots and dead spots.

Picture throwing two rocks into a pond right next to each other. Where the ripples line up, the splash gets bigger. Where they crash into each other, the water flattens out. Speakers do exactly that with sound waves. Push two of them together and you build loud patches and dead patches into the room on purpose.

Diagram showing two event speakers angled apart to reduce coverage overlap — If two speakers have to sit near each other, angle them apart so their coverage patterns overlap as little as possible.

Speaker placement diagram for covering a wide room evenly with multiple speakers — To cover a wide room, spread the speakers out rather than clustering them, so each one takes its own section of the audience.

Splay: how wide does your speaker actually throw?

Side view and top view of a powered speaker showing its 60 by 90 degree splay coverage angle — Splay is the cone of sound a speaker throws. This box covers 60 degrees vertically and 90 degrees horizontally, but not every speaker is 60 by 90, so check the spec for the model you actually have.

Think of a speaker like a flashlight that shines sound instead of light. The beam comes out as a cone, and the cone gets wider and softer the farther it travels. Splay is just how wide that cone is. Some boxes have a tight beam that throws straight down the room. Others spread wide so more people are covered up close.

Every model has its own splay angle. Look up the number for the speakers you actually have. Assuming everything is 60 by 90 is how rooms end up with a hot center aisle and nothing on the outside tables.

Point source, column array and line array

Slide explaining what a column array speaker is and where it works best for events — A column array stacks many small drivers in a tall narrow line, so it throws sound across the room instead of at the ceiling and floor. It is our go to in hard walled rooms with lots of glass.

Comparison of standard point source speakers versus a line array for event sound coverage — A line array is engineered so many small boxes behave as one controlled beam. Stacking ordinary speakers on top of each other does not achieve the same thing.

Coverage prediction maps comparing a standard speaker against a line array across a venue — Coverage prediction for the same room. The standard box runs hot at the front and dies at the back, while the line array holds a far more even level from the first row to the last.

Stacking normal speakers is like pointing a handful of flashlights at the same wall. You get bright patches and dark patches rather than one smooth, even wash. A properly designed line array is built so all those small boxes behave as a single controlled beam, which is why a big ballroom or an outdoor concert gets one instead of four speakers on sticks.

Quick troubleshooting: what to check first

Event audio troubleshooting checklist for a dead microphone, distorted sound, feedback and poor coverage — The four problems that come up most at events and the first things to check for each one before you start changing settings on the console.

Work these in order. Nine times out of ten the answer is in the first two.

Microphone not working: power, battery, mute switch. In that order.
Distorted sound: gain set too high, or the microphone is sitting too close to a speaker.
Nobody can hear in the back: volume level, speaker placement and splay, and how high the speakers physically sit. Speakers on the floor get absorbed by the first three rows of people.
Feedback and squeal: the microphone is pointed at a speaker, or the gain is too high. Move the microphone behind and away from the speakers.

When to bring in an audio team

Everything above is enough to run a small meeting, a classroom or a backyard event on your own. The point where people call us is usually one of three: the room is bigger than a couple of speakers can cover, there are more than two or three microphones live at once, or the event is the kind where sound failing is not survivable. A keynote, an awards night, a livestream, a general session with the whole company in the room.

If you want the gear without the crew, our rental prices are published on the site, including powered speakers, wireless microphone systems and mixers. If you want the crew, tell us about the room and we will tell you straight what it needs. We cover Salt Lake City, Park City, Ogden, Provo and the mountain towns from our Northern Utah warehouse.