How to Duplicate Mono Mic to Stereo in OBS Studio

If you are recording or streaming with a mono microphone in OBS Studio, your audio might only come out of the left or right channel, creating an unbalanced listening experience. This guide provides a direct, step-by-step walkthrough on how to use the Advanced Audio Properties in OBS Studio to duplicate your mono microphone input across both the left and right stereo channels, ensuring balanced dual-channel audio for your audience.

Step 1: Open the Advanced Audio Properties

Launch OBS Studio and look at the Audio Mixer dock, which is typically located at the bottom center of the screen. Find your active microphone or auxiliary input source. Click on the three vertical dots (or the gear icon in older versions) next to your microphone volume slider, and select Advanced Audio Properties from the drop-down menu.

Step 2: Locate the Mono Checkbox

A new window will open displaying a grid layout of all your active audio sources. Find your microphone in the list under the Name column. Look across the row for your microphone until you find the column labeled Mono.

Step 3: Enable Mono Downmixing

Check the box in the Mono column next to your microphone. When this option is enabled, OBS Studio automatically takes the single active channel (usually the left channel) and duplicates it to both the left and right channels of the stereo output.

Step 4: Configure Track Routing (The Audio Matrix)

On the far right side of the Advanced Audio Properties window, you will see numbered columns from 1 to 6 under the Tracks header. This is the routing matrix. * Ensure that the tracks you want to record or stream your microphone audio on are checked. * By default, checking Track 1 is sufficient for standard streaming. If you are doing multi-track recording, ensure the appropriate tracks are selected for your microphone.

Step 5: Test Your Audio

Close the Advanced Audio Properties window. Speak into your microphone and observe the green/yellow/red volume meter in the Audio Mixer. Both the top and bottom bars of the meter should now bounce in unison, indicating that the signal is being duplicated equally to both the left and right channels. Run a quick test recording to confirm that you can hear your voice in both ears.