no sound with williams rom with equalizerAPO for SSF on windows 11

[TeteDampoule]

I know this is specific and I finally found a solution.
I am not even sure that it is caused by vpinmame or be solved inside vpinmame.

This problem is specific to williams rom.
For some reason when using SSF 7.1 (surround sound feeback), sound is directed to the center channel which does not exist because in fact we usually use 6 channels (no sub, no center)
Rom sound is supposed to be on 2 channels only

A windows option redirect this center channel so usually there is no problem.
But when using equalizerAPO on windows 11 this trick doesn't work (for me). if case someone search for a solution see:
https://www.pincabpassion.net/t8926p500-tuto-surround-sound-feedback#249541

I dont remember having issues on windows 10.

The question is :
Why Williams roms output sound is different from other roms ? Center versus L+R
Could vpinmame modify Williams rom sound so it is equivalent format as the other brands ?
There is an option in vpinmame to expend sound to stereo but it didn't do the trick