Eliminating Microphone Buzz: 11 Top Reasons and Fixes

• Struggling to get a clean signal?
• Dealing with a buzz that’s driving you nuts?
• Learn how to troubleshoot buzzing and other unwanted microphone noise.

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There are few things more frustrating than a buzzing microphone. Low-level hum and hiss can completely ruin a recording, and no amount of post-production editing can fully correct the issue.

This article serves as a comprehensive guide to help you solve your microphone buzzing issues, and also prevent it from happening in the future.

Why Your Microphone May Be Buzzing

1. Wireless Device Interference

Wireless devices can cause static noise in a microphone due to electromagnetic interference (EMI). This occurs when the wireless device emits radio frequency signals that interfere with the microphone’s signal,

This includes mobile phones or even landlines, speakers, radio receivers, circuit breakers, or a nearby smart home device or digital TV. However, this is most common in low-quality wireless devices with poor shielding.

If possible, turn off wireless devices or disable the WIFI connection before you start recording. This can also prevent another annoying accident: a cell phone suddenly ringing right in the middle of an otherwise perfect take.

If you’re shooting on a set or for an event where you absolutely need to use radio transmitters, try to keep them at least 10 feet away from any receivers and ensure that the transmitters are never set to the same frequency.

2. Unwanted Background Noise

“Silence on the set!”  

Your microphone might actually be fine, but is picking up unwanted background noise. This is a particular issue with condenser microphones, which tend to be more sensitive and can pick up even the most subtle room sounds.

One way to mitigate unwanted sound pollution entering your microphone is to put on a headset, increase your microphone gain, and walk around the room.

With the gain turned up, you can identify any sounds that can interfere with your recording, such as the humming of a refrigerator, or an air conditioning unit.

Warning! Just be careful when turning the preamp up, as you could introduce a feedback loop and ruin your headset, microphone, and even worse — your hearing. Steer clear of any surrounding speakers to avoid this (or better yet, turn them off).

If it’s impossible to completely mute that sound, position your mic and equipment as far away as possible. Perform another recording take and listen to the output to find out if you’ve eliminated the noise.

If you regularly record in situations with a lot of background sound, use dynamic or directional microphones instead of condenser microphones. These will give you more control over the sounds they pick up.

For more info, check out our guide to dynamic vs condenser microphones here. Also, read up on how polar patterns work.

3. Interference From LED Lights

LED lights are energy-efficient, however, some can affect the performance of wireless mics. In one road test, the noise floor rose by 15 dB the moment the LED lights were turned on!

Similarly to wireless devices, LED lights can introduce microphone buzzing sounds due to electromagnetic interference (EMI) caused by the LED driver.

You can avoid this problem by getting LEDs that are FCC-approved. If you have no control over the light bulbs—for example, you’re just setting up your audio device in a rented venue—run a scan before you set up. Check the noise floor before and after you turn off utility lighting and stage lighting. 

4. Low batteries

If you’re using a wireless mic, check if your batteries need to be replaced or recharged. When a battery is low, it may not be able to provide enough power to the wireless transmitter, causing the signal to weaken and become susceptible to interference. This can result in a buzzing or crackling sound in the recording.

5. Transmitters Too Close To Recording Signal

Ensure all your transmitters are about 15 feet away from your microphone and microphone antennas. Even mic antennas should be kept several feet apart. This is a common cause of microphone buzz for performers who perform side by side, including band members and actors. Ideally, antennas should be at least 10 inches apart.

Another issue is your transmitter batteries. They can generate interference if they don’t have the right output voltage. If you hear a lot of hissing and buzzing sounds, replace them with a new set.

6. Multiple Wireless Mic Setups

When you’re working with several wireless mics, there’s a chance that they’ll overpower each other’s frequencies. This is called intermodulation interference. It tends to happen if you work simultaneously with ten or more microphones.

If you’re dealing with this setup, adjust the mic frequencies so they don’t overcrowd and compete on the same level.

Also, consider getting a digital microphone system if you need more than 16 microphones. This is less likely to have a hissing sound and feedback.

7. Incorrect Squelch Control Settings

Squelch control is a feature found in audio equipment, such as radios and intercoms, that suppresses background noise or static when no signal is present. It works by setting a threshold level below which the audio signal is muted or attenuated, effectively eliminating unwanted noise

If your regular transmitters work fine, try turning off the system transmitter. Does the RF indicator light stay on? That’s a sign of low-level interference. To help fix this, try changing the squelch control.

You can adjust the settings until you eliminate any noise. However, if it’s a persistent problem, try muting the audio from the wireless receiver whenever you aren’t using the transmitter. This should stop the interference (or at least, minimize it). If that’s not possible, consider getting a wireless system equipped with special circuits.

8. Faulty Cables

Another cause of mic hissing and buzzing is a faulty cable. You can identify the culprit by muting the sound channels until you know exactly which one is causing the buzzing noise.

You can also easily identify if a microphone cable isn’t working and solve the problem just by switching it for a new one.

As a rule of thumb, always pick a high-quality XLR cable or USB cable with good shielding and connectors. These factors are most likely to affect your audio signal and quality.

However, even a good cable can get damaged over time, so if you’re going to record something important — check the cables so you won’t be caught off-guard.

9. Incorrect Software Settings

The buzzing problem may not be caused by the studio microphone or the music studio hardware but the settings in your software.

In many cases, hissing, buzzing, and audio dropouts may be caused by using a very low buffer size. Try adjusting to 512 or higher. This will remove the glitches, but you may find latency response becomes problematic for recording.

Why is buffer size so important? We’ll sidestep the boring computer speak, but in general the buffer size affects the size of the audio data that your computer processes in one go. The lower the setting, the more computing cycles your CPU requires. So if you set it too low, you’ll get stuttering and issues.

If that doesn’t work, try tweaking your audio levels for both recording input and listening volume. Turn off the microphone boost, which can cause peaks. If the problem persists, consider changing your computer software or sound card.

10. Pre Amplifier and Audio Interface Issues

Because your audio interface is the last line of defense before the audio is captured, it’s likely the hissing and buzzing are coming from earlier in the signal chain. Nevertheless, you’ll most likely hear a buzz if your preamps are pushed to the absolute max.

If so, turn your preamp halfway and amplify the signal earlier in the chain before it hits your preamp or interface. This adjustment is known as gain staging.

11. Faulty Headsets

Maybe the problem isn’t the recording but your listening device. Try plugging your headset/speakers into another device or power supply and listen to something else.

Or, listen to your recording with another headset. This will help you determine if your headphones or monitors are creating the buzz.

Troubleshooting Tips to Avoid Microphone Buzzing

1. Get a high-quality audio system: microphone, cables, transmitter, and receiver. Ensure that batteries are fully charged and all equipment is securely plugged into the power outlet. Be sure to run tests to eliminate any hardware issues. You should also ensure that all headset and mic connections are securely inserted into the ports. Even one loose cable connection, microphone wire, or ground issue can cause a buzz that will take a long time to correct.
2. Always check the preamp gain or input volume. This determines your microphone’s sensitivity. The right setting depends on your microphone’s power, diaphragm, and how your amplifier and interface work. Do a mic test and reduce the gain by about one to two decibels. See if that reduces any static or feedback.
3. Check the noise in your recording area. This is especially important if you are not in a studio, or you’re recording in an open or unfamiliar environment. Turn off all wireless devices you don’t need, and ensure the microphone can’t pick up any fans or air conditioners.
4. Adjust your microphone distance at least 10 feet away from speakers, amplifiers, and other devices. This eliminates feedback and static.  If you are working with multiple mics, block off the users’ positions on the stage so they don’t compete for space.
5. Show the artist you are recording how to hold and position the microphone they are using. When a person holds a mic too close or too far away, it will pick up breathing or distorted sounds in the air. Run a few mic checks before doing your first take.

Before You Go…

These tips can help prevent or resolve most microphone buzzing, hissing, or feedback affecting your sound quality. If you’ve tried everything and still have no luck. it might be time for a new microphone altogether.