Windows Master Volume is affecting OBS audio source volume

[jebarkas]

Master Volume should only control the volume that I'm hearing, it should have no effect on audio source volume in OBS.

In my case it does have an effect and looks like it's a bug (either OBS, Windows or headphones fault). Increasing/decreasing Master Volume increases/decreases volume in OBS, but turning it all the way down (muting it) in Master Volume brings volume in OBS back to 100% (probably because my App Volume is at 100%).

I can control the volume I hear without affecting OBS only by headphones buttons, but it's not synchronized with any displayed value in Windows.

 

[jebarkas]

Ok, I figured out a workaround using VoiceMeeter Banana.

1. First you have to select your audio device (bluetooth headphones that have this issue) in "Hardware Out" section by expanding "A1":

2. Make sure that A1 is active in Virtual Inputs section, under "Voicemeeter AUX".
3. Switch to "VoiceMeeter Aux Input" playback device in Windows Master Volume Control, on App level you can still use Default device. Volume set here doesn't make any difference as long as it's not 0.

4. Lastly, click on "Menu" and...

...and enable "Hook Volume Keys (For Level Output A1)", this way you can control the volume with keyboard as you normally did with Windows Master Volume Control - it won't show the volume change in a popup, but it works.