How to Use the Streamlabs Audio Mixer

Before you start

The Streamlabs audio mixer controls the audio sources in your scene, such as a microphone, desktop audio, capture card, or media source. You manage these levels locally in the Streamlabs desktop application before they are sent to a stream or recording. Online services are only involved when you go live or export a file; mixer changes themselves are applied on your computer.

Have the physical device connected and recognized by the operating system before opening Streamlabs. If you plan to use a microphone, headset, capture source, or external audio interface, confirm that it appears as an available device in your system sound settings. Close other applications that may be using the same input or output device during the initial setup.

The default mixer shows the sources currently present in the active scene. A source that is not added to the scene will not appear in the mixer, so add the relevant capture source first if you do not see an expected device.

Step-by-step instructions

Open the mixer and identify the channels

Open the Streamlabs desktop application and look for the audio mixer panel. It is usually shown near the bottom of the main interface, next to the scene controls. Each channel represents one active audio source or device.

Common channels include the microphone or auxiliary input device that carries your voice, and desktop or system audio that carries sounds from the computer. A capture card, browser source, game capture, or media file may appear as its own channel depending on how the scene is set up.

Set the input and output devices

Open the audio settings from the settings menu and select the intended microphone or auxiliary input device for the main input. Choose the correct output device if you are sending monitoring audio to headphones or speakers. This device routing is separate from the volume level shown on the mixer channel.

If a source has its own device selection, such as a capture card or video capture source, select that device in the source properties rather than relying only on the global input setting. This is important when you use multiple cameras, capture sources, or audio inputs at the same time.

Adjust the input level with the channel slider

Speak or play the source at a normal level and watch the meter on the channel. Raise or lower the slider until the loudest normal peaks stay clearly below the red area. The goal is a strong signal without clipping or constant peaking.

Adjust the desktop audio and microphone separately. A quiet microphone can get lost under game audio, music, or another application, while a very loud input can push the overall mix into distortion.

Set monitoring and audio filters

Monitoring lets you hear a source through the selected output device. Use monitoring when you need to check a microphone or an external source with headphones. Keep monitoring off for sources that would create an echo or duplicate the sound you already hear.

Filters are edited from the channel menu or settings for the individual audio source. Common filters include a noise gate, noise suppression, compressor, and gain. These affect the source before it reaches the main mix, so place gain or noise reduction before other adjustments when the order matters.

Balance several sources together

Start with the voice channel, then bring in game or desktop audio until it supports the voice without covering it. Mute a channel when its source is not needed, or use the solo or monitoring controls to isolate one sound while leveling the rest.

For a recording or stream, run a short test with all sources active. Listen to the result at the same general loudness your audience would use instead of judging only by the visual meter.

Check the output

Verify the mixer by watching the meters during a short test recording or stream preview. Speech should rise clearly above the quieter background, while loud game moments should not push the input into constant clipping. If using monitoring, confirm the chosen output device matches the device you are actually wearing or listening to.

Review the recording to check how the mix behaves at different moments. The encoder, bitrate, recording format, and sample rate affect the final file, but the mixer determines the relative balance between sources. A recording with a weak microphone level may need a channel boost or a filter change rather than a higher output volume.

Common problems and next steps

If a source is missing from the mixer, check that the source has been added to the current scene and that its audio device is still available. A USB microphone, capture card, or interface that was disconnected or taken over by another application may disappear until the device is reconnected and Streamlabs is restarted.

If the microphone is too quiet, raise the channel input level first, then add gain only if the raw signal is genuinely low. If the voice is uneven, a compressor can reduce the distance between quiet and loud parts. For background noise, try a noise suppression or noise gate filter and adjust the threshold gradually so the voice is not cut off.

If you hear an echo or delayed duplicate, review the monitoring settings and the output device. Hearing a source normally while Streamlabs also monitors it to the same output can create doubling. Likewise, an open microphone near speakers can feed output back into the input and cause a loop.

If the stream or recording sounds distorted despite reasonable meters, check the overall mix and any strong filters. Lower the hottest channel, bypass filters one at a time to identify the cause, and confirm the encoding and bitrate settings are suitable for the content. Frame rate and recording format affect playback smoothness and compatibility, but audio distortion is usually caused by levels or processing before encoding.

After any device change, run another short test before the main broadcast. Reversible changes such as channel levels, mute state, monitoring, and filters can be adjusted without recreating the source, so keep a working baseline and make small changes one at a time.