How to Reduce Background Noise in OBS: Noise Suppression, Noise Gate, and Compressor Filters
Fan hum, a loud keyboard, traffic outside, the hiss of a cheap mic: background noise is one of the most common problems on small streams. The good news is that OBS Studio has free built-in audio filters that handle a lot of it. The bad news is that using them in the wrong order, or with extreme settings, can make your voice sound robotic or choppy.
This guide explains what each relevant filter does, what the OBS documentation says its defaults are, and a sensible order to chain them in. It is based on the OBS Knowledge Base articles linked at the bottom. The right values depend on your mic and room, so treat the numbers here as starting points to adjust by ear, not as tested “best settings”.
Before filters: fix the source
Filters work best on audio that is already reasonably clean. Before you touch them:
- Move the mic closer to your mouth. This raises your voice relative to everything else, so every filter has an easier job. (More in our USB vs XLR microphone guide.)
- Point the back of the mic at the noise source, if it’s a cardioid mic.
- Set gain properly. Your voice should peak in the yellow on the OBS meter, not the red.
- Turn off duplicate processing. If your mic software or another app already applies noise removal, doing it twice in OBS can degrade the sound. NVIDIA gives the same advice for its Broadcast app.
Free tool: Planning an audio upgrade for a noisy room? The Streaming Gear Budget Builder takes room type into account.
How to add filters
In the Audio Mixer, click the gear icon (⋮ or ⚙) next to your microphone and choose Filters. Click + at the bottom left to add a filter. Filters run top to bottom, so order matters. You can drag them to reorder.
The filters that matter
1. Noise Suppression: removes steady background noise
The OBS Knowledge Base describes Noise Suppression as a way to remove mild background noise or white noise, effective for things like PC fan noise and environmental hum, and not very effective against large amounts of noise such as a loud room.
You choose a Method:
- RNNoise is the default. OBS describes it as higher quality at the cost of more CPU usage. It was added in OBS 26 as an AI-based method with much better results for voice than the older Speex option.
- Speex uses less CPU and lets you set a Suppression Level (default −30 dB). Moving the slider further left makes it stronger, but OBS warns that stronger settings can distort your voice.
- NVIDIA Noise Removal appears if you install NVIDIA’s Broadcast SDK redistributable for supported NVIDIA RTX graphics cards. In newer OBS versions, NVIDIA’s audio effects may appear as their own filter rather than inside Noise Suppression. NVIDIA’s Broadcast app lists a GeForce RTX 2060 (or equivalent RTX) as the minimum GPU, on 64-bit Windows.
Starting point: add Noise Suppression with RNNoise. If your CPU is struggling, try Speex at its default level instead.
2. Noise Gate: silence between sentences
A noise gate mutes your mic when the level falls below a threshold and opens it again when you speak. OBS’s description: it cuts off background noise while you are not talking. Set the close threshold just above the noise level and the open threshold slightly below your speaking level.
OBS defaults:
| Setting | Default |
|---|---|
| Close Threshold | −32 dB |
| Open Threshold | −26 dB |
| Attack Time | 25 ms |
| Hold Time | 200 ms |
| Release Time | 150 ms |
How to tune it:
- Stay silent and watch your mic’s meter. Note roughly where the noise floor sits.
- Set the close threshold a few dB above that.
- Speak quietly, as you would at the end of a sentence, and set the open threshold a few dB below that level.
- If the ends of words are cut off, lower the thresholds slightly or increase hold or release time.
A gate doesn’t remove noise while you speak; it only silences the gaps. Used with Noise Suppression it works well, but don’t set it so aggressively that your voice chops in and out. Viewers find that more distracting than a little hum.
3. Compressor: evens out loud and quiet
OBS explains that a compressor automatically lowers the volume when your mic spikes louder, for example when you shout, and brings it back up when you return to normal. In short, it makes loud sounds quieter, so your overall level is more consistent.
OBS defaults:
| Setting | Default | What it means |
|---|---|---|
| Ratio | 10:1 | How hard it compresses above the threshold. OBS notes 2:1 is weak and 6:1 much stronger. |
| Threshold | −18 dB | Level where compression starts |
| Attack | 6 ms | How fast it reacts |
| Release | 60 ms | How fast it lets go |
| Output Gain | 0 dB | Make-up gain to bring the average level back up |
Starting point: a gentler ratio such as 3:1 or 4:1 often sounds more natural for speech than the default 10:1. Set the threshold so the compressor only acts on your louder moments, then add a few dB of output gain if you sound quieter afterwards. Adjust by ear.
4. Limiter: a safety net against clipping
A limiter is a compressor with a very fast attack and a very high ratio. It stops your audio from going above a set level. OBS recommends it as the last filter in the chain. Default threshold is −6 dB, with a 60 ms release.
The limiter can’t fix clipping that happens before OBS (at your interface or USB mic). It only stops OBS’s output from going over.
A sensible filter order
Put them on your microphone source in this order:
- Noise Suppression (RNNoise)
- Noise Gate
- Compressor
- Limiter (always last)
The OBS Compressor documentation describes the compressor as typically placed at or near the beginning of a chain, and some streamers put it before noise suppression. Our order puts noise removal first so the compressor doesn’t raise the noise along with quiet speech. Both approaches are used; listen and keep whichever sounds better with your mic.
Optional extras:
- Gain at the very top if your mic is too quiet even with the interface turned up.
- Expander as a softer alternative to the noise gate. It turns quiet sounds down rather than off.
- VST plugins for EQ or de-essing if you want to go further.
Bonus: duck your game audio when you talk
The OBS Compressor filter has a Sidechain/Ducking Source. Put a Compressor on your Desktop Audio, set the sidechain source to your microphone, and game audio dips automatically while you speak. OBS suggests these starting values:
- Ratio 32:1
- Threshold −36 dB
- Attack 100 ms
- Release 600 ms
- Output gain 0 dB
Troubleshooting
- Voice sounds robotic or underwater: noise suppression is too strong. Use RNNoise rather than very aggressive Speex settings, or reduce suppression.
- Words get cut off: noise gate thresholds too high, or hold/release too short.
- Noise “breathes” in and out: the compressor is raising the noise floor between words. Lower output gain or put noise suppression earlier.
- Still hear keyboard clicks while talking: filters can’t separate a click that happens at the same time as your voice. Use a quieter keyboard, move the mic closer to you and further from the keyboard, or point its back at the keyboard.
- High CPU usage: switch Noise Suppression to Speex, or on supported RTX hardware try NVIDIA’s option.
Bottom line
Fix the source first: a closer mic, sensible gain, a quieter room. Then add Noise Suppression, a gentle Noise Gate, a Compressor and a Limiter, in that order, and tune each by ear while watching the meter. Small adjustments beat extreme settings every time.