@ geneSW

Not exactly sure what you are attempting to do,
but if you 'Add Input',
select 'Audio Input'
and choose 'vMix Audio - System Mix'
you should "capture" whatever audio is being processed by your soundcard to play on your computer speakers or whatever device it is sending the signal to.

The caveat is that depending on your set-up and what you are doing, you can potentially run into feedback, echo or looping issues if you have other audio sources as well and do not route the audio appropriately.

I hope that answers your question somewhat.


Ice