How to Add Noise Gate to OBS (Stop Mic Picking Up Everything)

A noise gate does exactly one thing: it mutes your microphone when you are not talking. That is the entire feature. It does not clean up your voice, it does not remove hum from underneath your voice, and it cannot tell a keyboard from a consonant. It watches the level, and when the level falls below a number you chose, it closes.

Which means a noise gate is not really a filter you install. It is five numbers you measure. Copy someone else's numbers from a video and you get one of two outcomes: a gate that never closes, or a gate that eats the first word of every sentence. Both are worse than no gate at all.

This page is how to measure your own room, set those five numbers against it, and read a gate that is already misbehaving.

Where this page sits: how to reduce background noise in OBS is the page about which noise problem you have and which OBS tool solves it. This page assumes you already know you want a gate, and is the tuning manual for that one filter.

What the Gate Is For, and What It Is Not For

There are two kinds of unwanted sound in a recording, and a gate only helps with one of them.

Steady noise sits under everything you say: a fan, an air conditioner, the hiss of an inexpensive interface. While you are talking the gate is wide open, so it does nothing at all about this. Noise Suppression is the filter for that.

Occasional noise lands in the spaces between sentences: keyboard clatter, a chair creaking, a car outside. That is the gate's territory. It shuts the microphone during those spaces, so the spaces contain nothing.

The two are complementary, and the order they run in matters, which is the next section.

The One Prerequisite

Put Noise Suppression above the Noise Gate in the filter list.

This is not a stylistic preference. A gate compares the incoming level to your thresholds. If the signal still carries a constant hum, that hum raises the level the gate is measuring, so you have to set your thresholds higher, so the gate starts swallowing quiet speech. Worse, every time the gate opens the listener hears the hum switch on with your voice, which is far more noticeable than steady hum ever was.

Clean first, gate second. If you have not added suppression yet:

1. Find your microphone in the Audio Mixer dock.
2. Open its filter list from the gear or three-dot menu beside the fader.
3. Use + at the bottom left to add Noise Suppression, set to RNNoise unless CPU headroom is tight.

Level is the other prerequisite. When a microphone arrives so quietly that speech barely leaves the green band, no threshold anywhere can tell your voice apart from your room. Fix the hardware gain first, and note that the OBS fader is not it: the microphone setup guide explains where the real control lives on each kind of rig.

Adding the Gate

In the same Filters window, click + again and choose Noise Gate. Drag it so it sits below Noise Suppression in the list, because OBS processes filters top to bottom.

You now have five controls and a set of defaults that suit nobody in particular.

Measure Your Room First

Do not touch the sliders yet. Spend two minutes collecting three numbers, and the settings fall out of them.

Keep the Filters window open beside the mixer so you can watch the meter while you work.

1. The floor. Sit still and completely silent for ten seconds. Watch where the meter rests. That is your room floor. In a normal home office it usually sits between -60 dB and -45 dB.
2. The nuisance. Do the thing you are trying to gate out. Type at your normal speed, shuffle paper, whatever it is. Note the peak. Mechanical keyboards typically land around -45 dB to -35 dB.
3. Your quietest speech. Say a full sentence at the softest volume you genuinely use, the way you trail off at the end of a thought, not a test voice. Note the low end of that range. For most people it is -30 dB to -20 dB.

Write all three down. Everything below is arithmetic on those numbers.

The Five Numbers

Close Threshold and Open Threshold

These two are the gate. The gap between them is hysteresis, and it exists for a reason: with a single threshold, a signal hovering right at that level would open and close many times a second, producing an audible flutter that is instantly recognisable as a badly set gate.

Set Close Threshold a few dB above your measured nuisance peak, so keyboard clicks stay underneath it. If your keyboard peaks at -40 dB, -36 dB is a sensible close threshold.

Set Open Threshold 5 to 10 dB above that, so roughly -30 dB to -26 dB in the same example, then check it against your third measurement. The open threshold has to sit comfortably below your quietest real speech. If your soft sentences arrive at -28 dB and your open threshold is -26 dB, the gate will not open for them and you will sound like you are dropping out.

If those two constraints conflict, meaning your keyboard is genuinely louder than your quiet speech, no gate setting fixes it. Move the microphone or move the keyboard. That is the last section of this page.

Attack Time

How quickly the gate opens once the open threshold is crossed. Keep it fast. Anything above roughly 25 ms starts shaving the front off plosive consonants, so "put" arrives as "ut". There is no benefit to a slow attack on a speaking voice.

Hold Time

How long the gate stays open after the level drops below the close threshold. This is the control nobody touches and almost everybody needs.

Speech is not continuous. There are short gaps inside sentences, between words, in the stop before a hard consonant. With no hold, the gate slams shut in those gaps and reopens immediately, which sounds like your voice is being chopped into pieces. 200 ms is a good default. If your delivery includes long pauses inside sentences, go to 300 ms.

Release Time

How the gate fades down rather than cutting. 150 ms sounds natural. A very short release sounds abrupt and mechanical. A very long release lets the noise back in for a moment after every sentence, which defeats the purpose.

Reading a Gate That Is Misbehaving

Symptoms map cleanly onto controls, and this table is much faster than guessing.

That last one deserves expanding. If a Compressor sits above the gate in the filter list, it lifts quiet sounds toward your speaking level, which is precisely the distinction the gate is trying to make. Compressor after the gate, always.

When an Expander Is the Better Filter

OBS ships an Expander, and for a lot of people it is the better fit.

A gate is binary: open or closed. An expander is proportional, turning quiet material down by a ratio rather than muting it. The result is a gate that never announces itself, at the cost of never fully silencing anything.

Choose an Expander if you speak softly, have a wide dynamic range, or found the gate audible no matter how carefully you tuned it. Choose a Noise Gate if the noise is loud and distinct, a mechanical keyboard being the classic case, and you want it genuinely gone. The measurement process above applies to both, since the expander's threshold is set the same way.

What a Gate Will Never Fix

Being honest about the ceiling saves a lot of time in the sliders.

• Noise while you are talking. The gate is open then. Whatever is in the room is in the recording.
• Noise louder than your voice. A filter keyed on level cannot separate two things at the same level. Moving the microphone closer raises your voice relative to everything else, and nothing in software works as well as that.
• A reflective room. Gating does not remove the roominess of your voice, it removes it from the gaps, which can make the contrast more obvious rather than less.
• A microphone aimed at the wrong thing. A cardioid microphone rejects sound arriving from behind it. Point its back at the noise source before you touch a single filter.

Audio that crackles, drops out or arrives distorted is a different fault entirely, and no gate setting touches it. Begin with the crackling microphone guide instead.

The Alternative to Tuning Any of This

The setup above is a one-time job, and once measured it holds. It is also five numbers, a measurement pass and a filter chain standing in front of someone who wanted to record a five minute walkthrough.

Cubix Capture inverts the order. Nothing is predicted in advance by a threshold, because nothing has to be: the microphone and system sound come in together, and the pauses and stumbles get dealt with afterwards, against a take that already exists, where a wrong decision is reversible. Available on Windows and macOS, free tier included, if you want something to hold a tuned OBS chain up against.

If you are streaming live, a gate is genuinely the right tool and it has to be tuned before you go on air, because live has no afterwards.

Keep Reading

• Which noise tool for which problem, plus the order the whole chain runs in.
• The settings around the filters: sample rate, bitrate, levels and loudness.
• Gain staging before any filter exists, which decides whether a gate can work.
• A signal that arrives broken rather than merely noisy.
• Doubling and echo, which sounds like a filter fault but is not one.