Audio distortion (sounds like in a tunnel?) when capturing audio from video clip

[DaveRN]

I've got a video clip embedded in a slide presentation I need to record (to make a clip showing the video on top of the slide).
I've removed any microphone as a source in OBS (only sources are screen and video capture).
When I play the slide with video, it sounds clear.
The recording of the slide/video with OBS sounds like a recording in a tunnel.
I read a few comments about echoes but these seem to refer to an enabled microphone which I've taken care to avoid.
Also the help I read doesn't match the current OBS version's options and dialogs.
Any ideas what I'm doing wrong?
Thanks!
Best Regards, Dave

 

[AaronD]

Does the slide audio come from the Video Capture Device? Or the Desktop Audio?

A common problem is that people want to capture what comes out of their speakers, as an easy way to get game audio, presentation soundtracks, or whatever, and so they use the Desktop Audio for that. Which is fine; that's pretty much what it's designed for. But then they want to hear themselves, and so they turn on the Monitor on for their mic. Because they only have the one set of speakers, they send the Monitor to the same place that the Desktop Audio is picking up from, and they wonder why they get two copies of the mic!

You have the mic off in that screenshot, so it won't be a problem itself, but the same can apply to anything else too.

Depending on how fast your computer's audio system is and how you perceive a short-delayed copy of the same thing, that second copy could be anything from a discrete echo, to a slightly weird sort-of dissonant sound, to a "tunnel", to several other things.

 

[DaveRN]

Does the slide audio come from the Video Capture Device? Or the Desktop Audio?

Apologies but I do not understand what these terms mean nor where to find their definition?
I'm trying to capture the audio as played by the PowerPoint presentation with no other source.
Thanks!

 

[AaronD]

I'm trying to capture the audio as played by the PowerPoint presentation with no other source.
Thanks!

Do you also want to hear it while you're capturing? The settings to do that, is where the problem starts that I described.