issue with Omni Surround 5.1 on Windows 11

Hello everyone.

I recently bought an "Omni Surround 5.1" sound card. I used it for a while before noticing that the system volume slider didn't control the output level; instead, I could only adjust the volume via my amplifier.

However, Dolby Digital Live works perfectly—meaning it successfully converts PCM 5.1 audio and transmits it via SPDIF.

Interestingly, I managed to fix the issue at one point, and the volume control seemed to work correctly—though not without quirks. For instance, setting the system volume to 0% produced the same output level as setting it to 100%. But, it broken back

I also noticed that when everything was "fixed," I was able to adjust the volume of each individual speaker within SBX Pro Studio.

(P.S. I had "5.1 Surround" selected in the speaker settings.)

(p.s.s Sorry, my English is at an intermediate level, so part of the text was written using Google Translate.)