How to fix audio volume in CFSM?

Hello,

I have several CDLCs with excessively loud audio (read: borderline deafening) compared to the usual average volume. I checked my collection with CFSM and in fact, while most CDLCs have a negative SongVolume (LF) between -5 and -9, those deafening CDLC have all positive values like 0, 1, 2...

I recalled seeing an option in CFSM related to adjusting the volume, and I was planning to decrease it by a couple of points for those loud CDLC, but then I noticed that the "Custom Mods" > "Auto Adjust CDLC Volume (POC)" function has a series of preset values including a "Target SongVolume (LF) = -7".

Is it just supposed to be left like that default? Should I try with -7, simply test it in-game, and then adjust further down if still too loud, or up if too low?

Does the function actually change the audio file itself? If that's the case, I guess it's best to first backup the CDLC, just in case the audio gets too low the first time and boosting it back may result in a more noisy audio. Or does it simply tell the game itself to apply a volume change when playing the audio file (like it happens for example in Rock Band games)?

Thanks!

EDIT: I went ahead and tried to start the audio volume adjusment feature in CFSM but it asks me to download an FFmpeg setup file at a certain URL, which however leads to a deleted website...