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Mix Minus Basics and Troubleshooting

Mix Minus is a method of creating a separate audio mix in a mixer that excludes one or more audio sources
to prevent feedback loops and echos.

External Audio Mixer

Consider the setup where you are sending the Master audio output from vMix into an external audio mixer and then bringing
back the audio from that Mixer into an Audio Input in vMix again.
This will create a feedback loop (where the audio echos and gets louder and louder until it is completely distorted)
Refer to the audio mixer's manual on using an auxiliary output, set this output to have volume levels from all sources
on the mixer except for (minus) the audio channel connected to the vMix output.

vMix Call

Consider the setup where you are sending the Master audio mix to your remote guests. Normally this would
cause an echo as that Master mix would normally contain the audio of the remote guest as well.
vMix solves this by automatically creating a Mix Minus mix in its audio mixer,
as a result it will never send the remote guest their own audio.
Therefore if the guest is still hearing an echo of themselves or other audio, this may be coming from the following:
1. vMix operator is using speakers or very loud headphones.

As the operator will be hearing the guest, they need to ensure that audio is not being fed back into vMix
via a microphone or camera audio that has been left turned on accidentally.
Solution: Use only headphones, check for any audio sources in the vMix audio mixer that should not be turned on and may be picking up audio from elsewhere.
2. Guest is using speakers or loud headphones.

In this instance, their own microphone will be picking up the rest of the vMix production, leading to a potential echo.
Most browsers will do their best to eliminate this but it reduces audio quality, so using headphones is a must.

Last Updated: Friday, May 15, 2020 3:35:44 PM