How to Configure the OBS Audio Mixer

What the OBS audio mixer does

The OBS audio mixer shows every active audio input and output in one panel. It lets you adjust levels, mute sources and monitor how loud each source is before it reaches a recording or stream. The mixer is not a replacement for an external audio interface, but it is the main place to balance sound inside OBS.

Before you start

OBS runs locally on your computer. You do not need an account or an online service for audio mixing. Make sure any microphone, camera audio, desktop audio or other input device is connected before opening OBS, because hardware detected later may need to be added manually.

Open the audio mixer

The Audio Mixer dock is normally visible in the lower area of the OBS window. If it is hidden, open the View menu, choose Docks and enable Audio Mixer. Each active audio source appears as a separate horizontal strip with a level meter, volume slider and mute button.

Add or confirm audio sources

Check the Sources list for the capture source that should provide sound. Desktop Audio and Mic/Aux are common default entries, but their names and arrangement can differ between OBS versions and setup choices. A video capture source may carry its own embedded audio, so keep its name visible in the mixer if you need sound from that device.

To add an explicit audio input, select the Add button in the Sources list, choose Audio Input Capture or Audio Output Capture, and pick the physical or virtual device required. Some devices support separate input and output capture, and the same device may appear under more than one name depending on the operating system.

Set a safe input level

Speak or play audio at a normal volume while watching the source meter. A healthy level usually spends most of its time in the green-to-yellow area without hitting the red peak zone. Drag the source volume slider down if the meter regularly peaks, or up if the signal is barely moving.

OBS volume sliders are software-level adjustments. They are useful for balance, but they do not replace correcting an overly quiet or noisy device in the operating system or the device's own controls.

Adjust advanced audio properties

Click the gear icon next to a mixer source and choose Advanced Audio Properties. This opens a table of audio sources with options such as Sync Offset, Mono downmix and individual audio monitoring. Use Sync Offset when video and audio arrive a little apart; a small positive or negative value can move the audio earlier or later relative to the picture.

Monitoring behavior is controlled through separate Audio Monitoring options. The exact choices and labels can vary by OBS version, so check the installed version's interface rather than assuming a path from older releases.

Manage output and monitoring devices

Open Settings and select Audio to review the global audio devices. The Desktop Audio and Mic/Aux sections determine which output device or input device OBS uses by default. If a source has already been added as a dedicated capture in the Sources list, avoid also routing the same hardware through these defaults unless you intend to capture it twice.

The sample rate setting should be consistent with the rates used by your devices and system audio. Mismatched sample rates can cause distortion, drift or unexpected resampling. Changing this setting affects OBS audio processing, so note the previous value before testing.

Check the output

Make a short local test recording rather than testing audio changes on a live stream. Play it back and listen for clipping, imbalance between sources, sync problems or missing device audio. Watch the mixer during recording to see whether any unwanted source is active.

The final format, bitrate and encoding choices can affect how clean the result sounds, but they do not fix a source that is already clipping in the mixer. Confirm the source meter is under control before adjusting output quality settings.

Common problems and next steps

A source that is present but silent often needs a different device selected in its properties. A source that is missing from the mixer is usually not added or is disabled in the Sources list. Background noise from an unused microphone can be lowered with filters such as noise suppression or a noise gate, but first remove the offending source if it is not needed.

If audio and video gradually fall out of alignment, test a small Sync Offset in Advanced Audio Properties instead of repeatedly moving the slider. After making changes, create another short recording and compare it with the previous test.