Microphone static, buzzing or humming
Mic noise comes in flavors, and the flavor names the culprit: a steady low hum is electrical (usually a ground loop), crackle and pops point to USB or sample-rate trouble, and static that changes when you move the cable is the cable. Identify yours with a recording, then apply the matching fix.
Step-by-step fix
- Record the noise: run the CheckMyMic microphone test, record ten seconds of "silence", and play it back. Decide what you're hearing: constant hum, crackle/pops, or hiss — each has a different fix below.
- Steady 50/60 Hz hum = ground loop. On a laptop, unplug the charger and run on battery: hum gone means the charger's grounding is the culprit. Fixes: plug everything on the desk into the same grounded power strip, swap to a properly earthed (3-prong) charger, or add a ground-loop isolator on the audio/USB path.
- Move the mic off the USB hub. Unpowered hubs, keyboard passthrough ports and monitor USB ports both starve power and inject electrical noise — plug the mic straight into the computer, ideally a rear motherboard port away from other cables.
- Crackle and pops: match sample rates. On Windows, open the mic's Properties → Advanced tab and set the default format (say, 48000 Hz) to the same rate your app uses (OBS: Settings → Audio → Sample Rate). A mismatch forces live resampling that glitches under load.
- Check the cable: wiggle it at both ends while watching the tester's meter — bursts of static as you move it mean a broken shield or conductor, and the fix is a new cable (XLR and TRS cables die at the connectors first). Route audio cables away from power bricks and mains cables.
- Kill radio interference: move phones off the desk (GSM burst-buzz is unmistakable), and keep the mic and its cable away from Wi-Fi routers, monitor power supplies and cheap LED dimmers.
- Hiss (not buzz) that grows when you raise gain is a gain-staging problem, not interference — see the mic too quiet guide and add your gain earlier in the chain instead of boosting at the end.
Frequently asked questions
Why does the buzzing stop when I unplug my laptop charger?
That's the classic ground loop: the charger introduces a second path to ground, and the tiny voltage difference rides straight into the mic signal as 50/60 Hz hum. Use a properly earthed charger, put everything on one grounded power strip, or add a ground-loop isolator — running on battery just confirms the diagnosis.
My USB mic crackles and pops randomly — what causes that?
Three usual suspects, in order: a hub or front-panel port starving the mic of power (go direct to a rear port), a sample-rate mismatch between the OS and the app (set both to 48000 Hz), and a failing cable or port. USB selective suspend on Windows can also stutter audio — disable it in Power Options.
Is the noise coming from the mic or from my computer?
Test the same mic on another computer with the CheckMyMic mic test: noise that follows the mic is the mic or its cable; noise that stays with the computer is that machine's ports, power or electrical environment. This one test cuts the problem space in half — do it before buying anything.
I've tried everything and it still buzzes — what now?
Change one variable at a time: different port, different cable, different computer, charger unplugged. If noise survives every combination, the mic's own electronics are the source — and note that budget mics have a real self-noise floor: a faint constant hiss at high gain is inherent, and the practical fix is better gain staging or a software noise gate, not replacement cables.