I ran into this weird thing, which probably has to do with the software my headset uses to do surround sound in combination with Voicemeeter.
From the start, I have a Corsair VOID 7.1 headset. Now I know a headset with 7.1 is all emulated by the software and isn't actually 7.1...
Anyway, when I enable surround sound on my headset, everything sounds so nice and clear so I like to use it. The software that comes with the headset emulates the dolby surround sound into the headset.
The problem comes when I'm listening music (which is stereo) and I'm playing a game which has surround sound.
Every time more than 2 channels are used on my headset, the volume of the music lowers a tiny bit, and when there is no actual surround sound, it goes louder again.
To visualize this, in Voicemeeter I use the VAIO input for music (could be any input as its just stereo) and my AUX input for a game (which often use the 8 channels).
Each time I see the game use more than 2 channels (left/right) everything in my headset sounds lower. The music plays a little lower, and then when the game gets quiet and nothing is send through, the music goes louder again. I tested this as well with a 7.1 test file in VLC and the same thing happens, so its not the game doing something.
This only happens when I enable dolby surround sound on the headset.
The weird thing is that it only happens when I'm running Voicemeeter. When I shut down Voicemeeter and make the headset my default audio device, everything is fine.
What I assume is what happens is that Voicemeeter is sending the sound to the the headset like usual, but as soon as the software kicks in to emulate the surround sound (when another channel than left/right is used), it takes over or something and the volume changes a little.
I tried running the headset in exclusive mode or shared, but it makes no difference. I also don't have that setting enabled in windows that lowers my volume when a communication device is used or something.
I hope someone has a solution for this as it kinda is driving me crazy when listening music.