That is a good question that I don't have an answer to. Does centrafuse use the windows kmixer still to change volume or can volume adjustment be performed directly in DirectX? Maybe ask the developer or specifically in his forum. Or do some research on DirectX.
Ours is the age that is proud of machines that think and suspicious of men who try to.
ARCAUDIO SE Amps
Rainbow Profi CS365 & Profi Vanadium 12"
So leaving WAV and master volume at 100% and using winamp if needed to adjust output level is a good (simple) choice.
Bypassing kmixer with some type of kernel streaming plugin to winamp is a better sound quality choice (but more complicated install/configure/troubleshoot & may require resampling media files to 24-bit?).
Can someone expand on this a little?