Here is an 60 fps audio/video test file with a 440 Hz beep every 3s to test latency in OBS.
Just take a photo showing the original video screen and the OBS preview screen. The time difference of the two counters gives you the video latency. Seconds are shown on a decimal dial.
To calculate the audio latency record the original sound in the left and the OBS processed sound in the right channel and calculate the time difference by comparing both tracks in audacity.
Subtract the audio latency from the video latency and enter the resulting value (in milliseconds) as latency compensation in OBS for perfectly synchronous output…