A low, steady hum under your voice is one of the most common and most fixable streaming audio problems. It usually comes from your electrical setup, not your mic, and chasing it in the wrong place wastes hours. Here is a systematic way to find and kill hum.
Know what you are hearing
Electrical hum sits at a steady low pitch, around 50 or 60 Hz depending on your region, often with a buzzier harmonic on top. It is usually a ground loop: two pieces of gear connected to different ground points create a tiny voltage difference that leaks into your audio. Less often it is interference from a cheap power supply or a cable acting as an antenna.
Fastest suspects
| Cause | Tell-tale sign | Fix |
|---|---|---|
| Ground loop | Hum changes when unplugging USB/HDMI | Common power strip, USB isolator |
| Unbalanced cable near power | Buzz worsens near GPU/monitor | Balanced cable, reroute |
| Cheap power adapter | Whine that tracks GPU load | Better PSU/adapter |
| Dimmer/LED noise | Buzz tied to lights | Different circuit/bulbs |
Work the problem in order
Start by isolating: mute everything but the mic and listen. Then unplug devices one at a time, especially anything sharing an audio or USB path with the interface, and note when the hum changes. If disconnecting a capture card, second monitor, or laptop charger kills it, you have found a ground loop. The simplest cure is powering all your audio gear from the same power strip so everything shares one ground.
Targeted fixes
For a USB-caused loop, a USB ground-loop isolator or a powered USB hub often solves it. For interference on cables, swap unbalanced runs for balanced XLR/TRS and route them away from power bricks and the back of the PC. If a specific charger or adapter whines under GPU load, replacing that cheap power supply is the fix. Only after the hardware path is clean should you add a software noise-suppression filter, and even then use it lightly.
What not to do
Do not defeat the ground pin on a power plug to break a loop; it works but it is a genuine shock hazard. Use a proper isolator instead. And do not mask a strong hum entirely with heavy noise suppression, because aggressive filtering also thins your voice. Fix the source first; suppression should only clean up a faint residual, not do the whole job.
A repeatable diagnosis routine
Hum-chasing goes fast if you follow the same routine every time instead of randomly swapping cables. Start by muting every source except the mic to confirm the hum is on the audio path and not a game or app. Then unplug devices one at a time, especially anything sharing a USB, HDMI, or audio connection with your interface, and listen after each. The device whose removal kills the hum is your culprit, and if it is a capture card, second monitor, or laptop charger, you have almost certainly found a ground loop.
Fix loops with grounding, not by defeating safety. Putting all your audio and connected gear on one power strip so they share a single ground point cures many loops instantly. For a stubborn USB loop, a USB ground-loop isolator or a powered hub breaks the path safely. Only after the wiring is clean should you add a gentle software notch or suppressor to remove any faint remainder, and never lift a plug’s ground pin to silence a loop, because that trades a hum for a genuine electric-shock hazard.
FAQ
Why does the hum start only when I plug in my capture card?
That device is introducing a second ground path. Put it on the same power strip as your audio gear, or use an HDMI/USB isolator to break the loop.
Can software fully remove hum?
A notch filter or suppressor can reduce it, but strong hum should be fixed at the source. Software is a finishing touch, not a substitute for clean wiring.
Bottom line
Hum is almost always a ground loop or cable interference, so isolate it by unplugging devices, put all audio gear on one power strip, use balanced cables and USB isolators, and replace noisy adapters. Never defeat a ground pin for safety reasons, and treat software suppression as the last light polish after the real source is gone.
