- 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.
The only thing worse than a buzzing mosquito is a buzzing microphone. The humming, hissing, and buzzing sound isn’t just annoying, it can ruin your recording.
This is not something that can be fixed by adding special EQ and audio effects. Sometimes, these edits will even make it more obvious—and that still leaves you with the problem of how to prevent the buzzing sound from happening again.
Here’s Why Your Microphone May Be Buzzing
Let’s look at the different issues that can cause microphone noise and feedback and affect your sound quality.
1. Wireless Devices
If this is the first time your microphone ever malfunctioned, try recording something new in another setting. If the new audio sounds perfectly fine, chances are you just experienced wireless interference.
Certain devices can transmit signals that can cause microphone buzz and feedback. That can include mobile phones or even landlines, speakers, radio receivers, circuit breakers, or a nearby smart home device or digital TV.
As much as 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 make sure that the transmitters are never set to the same frequency.
2. Noisy Settings
“Silence on the set!”
Your microphone could be picking up 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.
Sometimes, these sounds are too soft for the human ear. One way to pick up sound pollution is to put on a headset, increase your microphone gain, and then circle around the room. You’ll be able to identify any sounds that can interfere with your recording.
If it’s not possible to completely mute that sound, position your mic and equipment as far away as possible. Do another recording 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 which kinds of sounds they pick up.
3. Lights
LED lights are energy-efficient and are often used to light up stages and event venues. However, some kinds of LED bulbs 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!
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. While the batteries obviously still work, if they’re running low on juice, they may cause low-level interference.
5. Transmitters
Make sure that 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. If they don’t have the right output voltage, they can generate interference. If you hear a lot of hissing and buzzing sound, 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’re working with 10 or more at the same time. As a general rule, you can only use 16 analog microphones simultaneously.
If you’re dealing with this kind of set-up, adjust the mic frequencies so that they don’t overcrowd and compete on the same level. If you need to work with 16 microphones or more, consider getting a digital microphone system. This is less likely to have hissing sound and feedback.
7. Squelch Control
If your regular transmitters are working 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 will be able to easily identify if a microphone cable isn’t working, and solve the problem just by switching it for a new one.
To avoid this problem, 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. But 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.
Planet Waves Classic Series microphone cables utilize ultra-pure, oxygen-free copper conductors for low capacitance and pure signal transfer.
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9. 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 microphone boost, which can cause peaks. If the problem persists, consider changing your computer software or sound card.
10. Pre Amplifier and Audio Interface
Because your audio interface is the last line of defense before the audio is captured, it’s likely the hissing and buzzing is coming from earlier in the signal chain. Nevertheless, if your preamps are pushed to the absolute max, you’ll most likely be hearing a buzz.
If this is the case, turn your preamp to 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, simply listen to your recording with another headset. This will help you figure out if your headphones or monitors are creating the buzz.
Troubleshooting Tips to Avoid Microphone Buzzing
First, get a high-quality audio system: microphone, cables, transmitter, and receiver. Make sure 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 make sure 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.
Second, always check the preamp gain or input volume. This determines your microphone’s sensitivity. The right setting depends on your microphone’s power and diaphragm, and how your amplifier and interface works. Do a mic test and turn down the gain by about one to two decibels. See if that reduces any static or feedback.
Third, check the noise in your recording area. This is especially important if you are not in a studio, or if you are recording in an open or an unfamiliar environment. Turn off all wireless devices that you don’t need, and make sure that any fans or air conditioners can’t be picked up by the microphone.
Fourth, 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 that they don’t stand too close together.
Fifth, show the artist you are recording how to hold and position the microphone they are using. Often 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.
Final Thoughts
These tips can help prevent or resolve most microphone buzzing, hissing, or feedback that can affect your sound quality. If you’ve tried absolutely everything and still aren’t having any luck, test each part of your signal chain. It might just be time for a new mic cable or pair of headphones.