Audio Input can be used to add multiple audio sources to vMix such as Microphones, USB audio devices and any sources compatible with the ASIO drivers.
Each of these inputs can be independently controlled from the vMix Audio Mixer, turning vMix into a fully fledged audio mixer alongside your video production.
Select the Audio Device or Microphone to add.
Some devices support multiple channels, you can select any stereo pair or a single mono channel here.
To add more than two channels, add multiple inputs selecting a different channel each time.