Question / Help Audio issues

[LacrimosaMelody]

I'm probably dense and missing this in the settings, but how can you stream audio and not have it 'echo'? I had audio output capture on, but it looks like OBS was also outputting audio as well as the game I was playing, so on stream it had the game audio, followed by an 'echo' from OBS.

https://gist.github.com/46b64644a46dbe097b89458addf3f7c6