If the game allows alt+tab you could try dropping the CD audio level in the Windows mixer. A bit of a daft solution I admit. Not got to my copy of Extreme-G2 yet, still in road racing games, futuristic racers are next!

I don't know if there are any 3rd party mixers that restore the ability to change volume levels of MIDI, WAV and CDA the way Windows used to have. I would love to find one. Short of that, you could try to apply _inmm to get the game to use ripped audio that you have set the volume lower with an audio editor. That's not an ideal solution since it doesn't exactly allow changing volume on the fly, but you could try to find a reasonable balance.

Ripping the audio and lowering it's dB reminds me of how that is the only way to lower music volume in PSO... It would defiantly work though, but if _inmm will bind properly to xtremeg2's executable is another story.

There is no CD Audio level in the windows mixer on Vista/7... All you can do is lower the total volume of the main executable's audio sink and nothing more. Thanks Microsoft for forcing us a "PulseAudio solution" to sound!

What on earth is that thing GOG uses to get CD Audio tracks as MP3's to play in i76, Incoming ,etc?

I am not familiar with GOG is using. I hasn't been in any of the GOG games that I have. As to _inmm it is a bit hit and miss, but you are not out that much by trying. While I do like having the means to vary volume per application, I do miss the ability to balance between audio devices. It seems like someone would have made a real mixer for Vista and later that will work by devices instead of by applications, but I didn't find one the time I looked.

The GoG releases I've seen use ogg-winmm, perhaps with GoG's own modifications. My experience with it is that it has less compatibility than _inmm. It's open source and more portable (doesn't need an install) though.

_inmm doesn't need to be installed either