ZDoom

Reading this, I think that tinkering with the different volumes of the various music players via altering the gain setting is not going to work that well - it might be better to actually boost the streamed sound data directly when copying it to the streaming buffer. There's just too little control and too stringent limitations on what it can do.

I have already done some evening out for the various MIDI devices because they had indeed some vastly differing base volumes, that should be better with the next release already.

The absence of FMOD in GZDoom 3.x made me tinker with music settings. I was delighted to find that there is now a separate volume slider for MOD music, but it has one drawback: you can't set volume lower than 1 in the GUI. Interestingly, lower values work even now - when you write something like [i]set mod_dumb_mastervolume 0.5[/i] to the console, the playback volume gets down. However, some rounding is in play in the current version, because volumes 0.3, 0.4 and 0.5 sound the same to me. Also, setting it to 0 doesn't mute the music. I don't know how hard it would be to fix that, but if it is, please at least make the GUI slider go down to 0.5.

Just in case somebody was curious why I wish this: it would help to (partially) resolve too quiet MIDI playback on some MIDI devices under Windows, about which I asked earlier:

https://forum.zdoom.org/viewtopic.php?f=7&t=45743

Ideally, I'd need separate volume slider for MP3/OGG/wave music too, but I'm grateful even for this.