Capture Card Latency in OBS

[pftq]

Almost bought a new capture card / second screen to avoid latency issues, but it turns out the solution was in OBS by 1) using capture only on the Properties > Audio Output Mode and then 2) Monitor + Output on Advanced Audio Properties.  For some reason, having Properties > Audio Output Mode set to Desktop introduces a 100+ ms delay.  Would've expected it to be the same as Monitor + Output.  If you're hearing an echo or need to also record sound from Desktop, you'll want to use Monitor Only (mute output) so it doesn't also record the capture card from desktop audio.