Advancemame does it, why isn't there such an option in mame yet?
I've tried various programs and volume programs in windows, but the auto sound in advancemame works fantastic and all the games play at the same level.
Macross Plus is a perfect example, works great in advancemame, i can't hardly hear anything in mame .129
I use Maximus Arcade for my FE, and i tweaked all my video previews to the same volume, but now i just have to deal with various sound levels in MAME, MK at least let me turn it up, but not all games have that option.
Any suggestions?