Enable Audio Enhancemnets --> Microsoft doing the job for you, again.
My case is that the speaker had significant bass loaded, very unusual and asking to be changed. To actually research this topic, ending up with this solution given here stole my time and is rather a matter of luck since this setting is way to deep down for any normal user. The EAE switch off immediately removed the issue of bad sound.
Once over, Microsoft is doing things in Windows 11 that NOBODY asked for. I have an extremely bad experience from Windows 10 to 11, in fact only with "matured" Windows 11. The very first months were all right. I know the OS since over 30 years.