OBS increases microphone volume over 20 seconds on every recording, why?

[MartinInCO]

Every time I record a video in OBS the microphone volume increases from soft to loud over 20 seconds. When I playback the video the volume increases. At 10 seconds and at 20 seconds the increase is more dramatic, but not after that. What is going on?

I've tried two different mics and it happens with both mics. I've recorded an audio in Audacity with one of the mics and it doesn't happen. So it seems to be an OBS 'feature'.

Is there a setting that would cause this to happen? Any help would be appreciated!

-Martin

 

[PaiSand]

Check any filter you may have added to the microphone in OBS or outside OBS.

Please post a log with your issue! Here's how...

OBS Studio creates a log file each time you run it which contains very useful diagnostic information. Without a log file, it's much harder for any support volunteers to figure out problems and your post may be ignored. To upload a log file, go to the Help menu > Log Files > Upload Last Log...

obsproject.com

 

[MartinInCO]

@PaiSand, thanks for your reply. I had no filters applied to this mic when I noticed it. I've added filter to try to fix it, but nothing worked.

I'm not sure what you mean by filters 'outside OBS'. Where would I look? Wouldn't filters outside OBS affect Audacity too if they existed?

Any other thoughts?

Thanks,
Martin

 

[R1CH]

Most likely there is some other application also using the Mic with "auto gain" or similar functionality. If you cannot find the source of this, you can lock the mic level using LockMicLevel from https://r-1.ch/.

 

[AaronD]

I had no filters applied to this mic...

There are several places a filter could be. Sources and scenes can both have them, and scenes can be used as sources in other scenes. With just that, the chain of processing can be arbitrarily long, and not necessarily intuitive.

And as has been mentioned already, the *entire* chain of processing extends outside of OBS. In both directions.
If the input side is changing, you'll see that change on OBS's meter. Do you?
If the output side is changing, you won't.

A *slight* possibility is that the *encoder* is trying to do some "auto gain" or "consistent level" sort of thing. What are your settings there?
If that's what's happening, then the Monitor should not do it. What happens if you send OBS's Monitor to a loopback, and record *that* in Audacity? That's probably not a practical solution, but it does provide a data point.

 

[MartinInCO]

I figured it out, thanks to everyone's input!

It's not OBS that's increasing the volume of the mic. It's my video player (PotPlayer) that increases the audio output at 7-10 and then at 17-20 seconds. When I play it in a different video player this doesn't happen. This has been driving me crazy!

Thank you all! -Martin