Mic Noise When Recording? How to Find and Fix the Cause

You hit record, stay quiet for a second and there it is: a soft hiss, a low hum or a whine that shouldn't be there. Microphone noise is one of the most common problems for anyone recording vocals at home. The good news: the cause is almost always something you can check yourself, without buying a new mic.

In this guide you'll figure out step by step what kind of noise you're hearing, where it comes from and how to get rid of it. At the source first, and only then in your mix.

Step 1: what kind of noise do you hear?

Not every noise has the same cause. Listen closely and see which of these sounds most like yours:

• Hiss: a high, constant "sssh" sound. It often happens when your gain is cranked while your voice comes in quietly.
• Hum: a low, steady tone. Typical of a grounding problem, also called a ground loop.
• Buzz or whine that changes: does the sound change when you move your mouse or when your computer is busy? Then it's probably getting in through your computer or USB connection.
• Background sound: a fan, fridge, traffic or heating. That's not electrical noise, that's your room.
• Crackling or dropouts: usually a broken or loose cable or plug.

Step 2: measure it first

Before you start turning every knob: make the noise visible. Our free mic test shows you right in your browser how loud your signal comes in and how much noise your microphone picks up. Use the noise measurement, stay silent for 3 seconds and you'll see your noise level. Then record 6 seconds and play it back. Your audio stays on your own device.

Handy trick: measure again after every change. That way you know exactly which step made the difference instead of guessing.

Cause 1: your gain isn't set right

This is the number one cause of hiss. If you're far from the mic or speaking softly, you end up turning the gain on your interface way up. That boost doesn't just make your voice louder, it also raises the noise from your preamp, your cable and your room.

What helps:

1. Get closer to the mic. Your voice comes in louder, so you need less gain. Use a pop filter so your plosives don't hit too hard.
2. Set your gain on your loudest part. Rap or sing the loudest section of your lyrics and set the gain so the signal comes in strong without going into the red.
3. Don't push your DAW fader instead of the gain. The fader only changes what you hear, not what gets recorded.

Not sure about the right level, or hearing distortion instead? Read distorted recording? how to prevent clipping. It explains exactly how to set your gain.

Dynamic mic with low output?

Some dynamic microphones need a lot of gain. If your interface is almost maxed out and it's still quiet, you'll hear preamp noise sooner. This comes up a lot with the well-known Shure SM7B. Here's how to deal with it: Shure SM7B too quiet? Gain, Cloudlifter and FetHead explained.

Cause 2: hum from grounding (ground loop)

A low hum often comes from a grounding problem. According to Focusrite, it happens when there's no proper path to ground, or when there are multiple paths to ground. That second one is called a ground loop. Focusrite says interfaces that draw their power over USB from your computer are the most susceptible.

Here's how to track it down:

1. Unplug your laptop charger. Is the hum gone when your laptop runs on battery? Then the problem is your charger or the grounding of the outlet. Focusrite recommends using your computer's official power supply instead of a third-party one.
2. Try a different USB cable. That's also on Focusrite's list for USB-powered interfaces. Sound On Sound notes that shorter cables often work better.
3. Disconnect devices one at a time. Speakers, a second screen, a MIDI keyboard: unplug them until the hum stops. Then you know which device adds the extra ground path.
4. Use the same power outlet. Does your interface have its own power supply? Then plug your computer, interface and speakers into the same power strip.
5. Use balanced cables to your speakers (TRS), but only if your speakers have balanced inputs.

If none of that works, both Focusrite and Sound On Sound mention a ground loop isolator: an inline box that breaks the ground loop between two devices.

Cause 3: cables and interference from other gear

Audio cables can pick up interference from anything that uses power. Focusrite mentions power cables, lights, amplifiers and computer hardware, among others. Long cables pick up more, and a coiled cable even acts like a kind of antenna.

• Use a cable that's no longer than you need, and fully uncoil it.
• Don't run your mic cable along or over power cables and power strips.
• Crackling when you move the cable? Try another one. A loose connection in a plug is a classic.

Cause 4: your room

Do you hear a fan, fridge or traffic in your measurement? Then it's not electrical noise, just sound in your room. Your mic picks up everything that's there, especially when you stand far away and crank the gain.

• Turn off fans, AC and other devices while recording.
• Keep your laptop as far from your mic as possible, or with a cardioid mic, point the back of the mic toward your laptop, since that's where it picks up the least.
• Record in a room with soft stuff, like a couch, curtains or a closet full of clothes.
• Get closer to the mic so your voice wins over the room.

Does your room echo too? Read acoustic panels for your home studio to learn what panels do and don't do.

Cause 5: settings in your software

Do you also use the mic for calls or gaming? Video call apps often use noise suppression and automatic gain. They make your voice clear in a call, but for music you want them off. Automatic gain turns your level up as soon as you go quiet, which makes the noise louder. In the mic test you can switch those browser filters on and off to hear the difference.

Also check that you picked the right input in your DAW. If your laptop's built-in mic is still set as the input, that's what you're recording, not your actual microphone.

Is a little noise normal?

Yes. Every microphone, preamp and cable makes a little noise. Focusrite says so too: a mic or cable can make some noise and still be well within spec. Do you only hear the noise with your headphones turned way up, and is it gone as soon as the beat is playing? Then there's probably nothing wrong.

Noise that's already recorded: cleaning up afterwards

Got a take with noise that you can't re-record? You can still do something about it:

• Cut out the silences between your lines. Where you're not rapping or singing, nobody hears noise.
• Use a noise gate or expander. It turns your track down as soon as you stop. Set it carefully, or you'll chop off the start and end of your words.
• Use noise reduction for constant noise. In FL Studio, Edison has a tool for that. Learn how in how to reduce background noise in FL Studio vocals. Always work on a copy and don't overdo it, or your voice will start to sound strange.

Keep in mind: compression and a bright EQ make your voice fuller, but they also bring up the noise. The cleaner your recording, the more you can do in the mix.

Checklist: fix mic noise in 8 steps

1. Figure out what you hear: hiss, hum, buzz, room sound or crackling.
2. Measure the noise with the mic test.
3. Get closer to the mic and set your gain again.
4. Unplug your laptop charger and listen if the hum disappears.
5. Try a different, shorter USB or mic cable.
6. Disconnect other devices one at a time.
7. Turn off fans and other noise makers.
8. Turn off noise suppression and automatic gain in your software.

FAQ

Why does my mic only hum when my laptop is charging?

That usually points to a grounding problem through the charger or the outlet. Test on battery, use the official charger and try a different outlet.

Will a more expensive mic fix the noise?

Usually not. Hum, buzz and room noise have nothing to do with the price of your mic. Check your gain, cables, grounding and room first.

Do USB mics get noise too?

Yes, the same rules apply. A USB mic also gets power from your computer and picks up room sound when you're far away.

Should I fix noise before I start mixing?

Yes, ideally while recording. Everything that makes your vocal louder and fuller in the mix makes the noise louder too.

Next: make your vocal sound good

Is your recording clean? Then the fun part starts. The free vocal chain cheat sheet shows you a complete vocal chain for Logic Pro and FL Studio in the right order, plus a checklist for a clean take. Want a ready-made chain you only need to load? Check out our vocal presets for FL Studio and Logic Pro.

Find more handy tools in our free music tools.