MicTester

OBS mic test: the same dBFS marks as your mixer

Processing off, meter marked at -20 and -9 dBFS — the two levels OBS Studio publishes for its own programme meter. Set your gain here before you go live, and the mixer will agree with you.

Sample trace

A drawing, not a recording — nothing here came from a microphone yet.

Spectrum

low → high frequency

Level (dBFS)

Peak -12.3|RMS -21.3|Hold −∞

−50−20−9−0.5−600

Reading: On target — that is the sample trace’s own peak, not yours.

Before the browser asks

  • · Your browser will ask for permission. Nothing happens until you allow it.
  • · The page then reads three things: the waveform, how loud you are, and the device list.
  • · No recording starts on its own. The recorder has its own button below.
  • · Audio is processed in this tab and never uploaded — there is no server to upload it to.
  • · OBS captures the device and applies its own filters afterwards. Switching the browser’s processing off gives you the signal OBS would see before any filter.

OBS is the one app that tells you its numbers

Conferencing apps give you a bar that wiggles. OBS gives you decibels, and its knowledge base publishes exactly where the coloured zones change. That makes it the only app in this cluster where a browser-based mic test can be made to agree with the application precisely, which is why this page adopts OBS’s thresholds outright instead of inventing its own.

The colour ranges in columns one and two are quoted from OBS Studio’s knowledge-base article “Audio Mixer Technical Details”, dated 2022-02-13, read directly on 2026-08-15, where they describe the input-level indicator at the far left of each mixer channel. The third column is this site’s own band name for the same range. That article states OBS currently implements a sample peak programme meter (SPPM), which is why the peak reading here and the bar there are measuring the same quantity. Nothing in this table was measured by us.
OBS indicator colour Range OBS publishes What MicTester calls it
dark green less than −50 dBFS Nothing arriving
light green between −50 and −20 dBFS Too quiet
yellow between −20 and −9 dBFS On target
red between −9 and −0.5 dBFS Hot
white larger than −0.5 dBFS Clipping risk

Two of those boundaries have names in the same article. −20 dBFS is the Alignment Level, and OBS explains the choice directly: the value was chosen to be near the average audio level for speech, and traditionally you play a sine tone through a whole equipment chain and set each device so it reads exactly there. −9 dBFS is the Permitted Maximum Level, above which OBS says there is a small but real chance the sound clips before it reaches the viewer.

The article also explains why the ceiling was set nine decibels below full scale rather than at it, and the reasoning is three margins of three: three decibels because a sample peak meter can under-read the true peak by that much, three more because peaks are hard to read off a moving bar, and three for alignment error across a chain of equipment. OBS notes that its peak-hold feature eliminates the middle one for anyone who uses it — which is why the meter on this page has a hold reading and a reset button. The eleven decibels between the alignment level and the permitted maximum are something else entirely: they are the room speech is expected to occupy above its average, which is why a crest factor of about nine decibels fits inside them.

Gain staging, in the order OBS insists on

The single most useful sentence in the OBS audio guide is that you always start at the device. The fader is the last adjustment, not the first, because everything before it has already decided how much signal and how much noise you have.

  1. The microphone or interface. OBS’s guide says to check for a physical knob, usually labelled Gain. This is where you win or lose.
  2. The operating system. OBS gives a specific Windows trick here: in the Sound control panel’s Recording tab, open the device’s Properties, go to the Levels tab, right-click the percentage value and choose decibels — then aim for around 0.0 dB for the least clipping. The setting persists when you switch the display back to percent.
  3. This page. Read the peak hold. If speech peaks land between the two marks, the first two steps are right and you can stop adjusting.
  4. The OBS fader. Only now, and only for balance against your other sources. OBS notes you can enter percentages above 100% in Advanced Audio Properties if you truly need more.
  5. Record a session and listen back before going live — OBS’s own final instruction, and the reason the recorder above exists.

Every OBS audio control worth knowing

Compiled from OBS Studio knowledge base, “Audio Mixer Technical Details” (article dated 2022-02-13); OBS Studio knowledge base, “Audio Mixer Guide” (article dated 2026-04-03); OBS Studio knowledge base, “Noise Suppression Filter” (article dated 2022-01-12); OBS Studio knowledge base, “Quick Start Guide” (article dated 2021-08-25). Checked on 2026-08-15. The OBS knowledge base states it is still a work in progress and asks that its pages not be linked to users, so it is cited here by article title and date rather than by URL.
Control Where What it does Browser equivalent
Mic/Auxiliary Audio device Settings → Audio The Quick Start Guide’s step 3 says OBS captures desktop audio and microphone by default, and to set the devices manually here if the mixer meters are not moving. deviceId
Fader Audio Mixer dock Post-capture volume, in dB. Adjust it last — OBS’s guide says to start at the device. none
Monitor button Audio Mixer dock Plays a source back through the monitoring device set in Settings. none
Noise Suppression filter Filters on the audio source Three methods are documented: RNNoise (the default, higher quality and more CPU), Speex (configurable, default suppression level −30 dB) and NVIDIA Noise Removal, which needs the NVIDIA Broadcast SDK installed. noiseSuppression
Downmix to Mono Advanced Audio section of the Audio Mixer Forces one-channel audio to both sides. OBS’s guide flags the symptom it fixes: only the first meter lighting means viewers hear you in the left channel only. channelCount
Audio Meter Decay Rate Settings → Audio How fast the meter bar falls back after a peak. none

Why a browser test is worth running at all when you have OBS

Because OBS shows you the signal after its own filter chain, and this page shows you the signal before anything. When a stream sounds wrong, the useful question is whether the raw capture was already wrong, and the fastest way to answer it is to look at the same microphone somewhere that has no filters at all. If the peak hold above sits at −38 dBFS with every switch off, no OBS filter will rescue you: you are amplifying a weak signal and the noise floor comes up with it. Fix the gain, then go back.

The second reason is speed. Loading OBS to check a microphone before a stream is a minute you may not have; this page takes ten seconds and gives you the same number. And if the microphone turns out to be dead, the Windows 11 page maps the browser’s exact rejection to the thing that is broken, which is more specific than “OBS shows no meter”.

FAQ

OBS mic questions

What level should my mic hit in OBS?

OBS publishes two marks and they are the whole answer. Its knowledge base puts the Alignment Level at -20 dBFS — chosen, in OBS’s own words, to be near the average audio level for speech — and the Permitted Maximum Level at -9 dBFS, above which there is a small chance the sound will clip before it reaches the viewer. Land your speech peaks between those two and you are done. The meter above is marked at the same two levels.

Why does this page turn all the processing off?

Because OBS applies its own filters after capture, and stacking browser processing on top of OBS processing tells you nothing about either. With echo cancellation, noise suppression and gain control off, the meter above shows the signal OBS would see before you add a single filter — which is the number you want when you are setting gain at the interface.

What is the difference between the four things moving on the OBS meter?

Four indicators, four jobs. The input level square at the far left shows the level arriving, before the fader but after any filters. The main peak programme meter bar has a length that indicates, in OBS’s own words, the peak volume level of what the viewer will hear. How fast that bar falls back afterwards is not fixed: it is the Audio Meter Decay Rate in Settings → Audio, listed in the control table above. The peak hold line keeps the loudest value for 20 seconds so you can catch a spike you missed. The black VU line is a root-mean-square average integrated over 300 ms, which tracks loudness rather than peaks. This page draws the equivalent of the last three: peak, hold and RMS.

Only one of my two meters lights up. What is wrong?

Nothing is broken — you have a mono source in a stereo slot. OBS’s guide is explicit: with a two-channel source, left is shown first and right second, and if only the first meter lights up your viewers hear that source in their left channel only. The fix it names is Downmix to Mono in the Advanced Audio section of the mixer. In this page’s track readout you can see the same thing as a channelCount of 1.

Which OBS noise suppression method should I use?

OBS documents three. RNNoise is the default and OBS describes it as higher quality at the cost of greater CPU usage. Speex is configurable, with a suppression level defaulting to −30 dB, and OBS warns that pushing it stronger can distort other sounds including your voice. NVIDIA Noise Removal appears alongside the other two only once the NVIDIA Broadcast SDK redistributable is installed. All three are available on Windows, macOS and Linux according to OBS’s own filter page.

My level looks fine in OBS but my recording is quiet. Why?

Because the input-level indicator sits before the fader, so pulling the fader down does not change it. OBS spells out the ordering: the input meter is before the volume fader but after any filters on the source, and to read a true input level you have to disable the filters. Set the level at the device first, as OBS’s own guide insists — a physical gain knob, then the operating system, then the fader last.

More from MicTester

Other things worth checking before you go live

  • the full mic test with every switch on one page — waveform, spectrum, dBFS meter, recorder and device picker together, with all three processing toggles exposed.
  • headset mic test — Confirms the boom mic and the earpieces are the same physical unit by matching the groupId the browser reports for each.
  • microphone not working on Windows 11 — Reads the browser’s actual rejection name and maps all seven specified failures to the thing that is broken on the machine.
  • Keyboard Tester — The same idea for the other input device: press a key, watch it light up, and see the exact event your browser received.
  • Click Speed Test — Counts clicks per second against the browser’s own timestamps, so the deadline holds even when the frame rate does not.