There’s a long list of mp3-related tools to come, and it’s a large part of what makes the M section so intimidating. It could be weeks before this is over.
mp3gain is next, a tool that reads peak levels and adjusts them for one file or for a whole album. This is what prevents particular songs from sounding “louder” than others on the same album, which can be annoying.
I am no longer an audiophile though, so as long as one song doesn’t whisper and then next one blast my eardrums, I usually don’t complain.
I do have a dash of OCPD though, and so the short time it takes to adjust the gain across an album is usually satisfying to me.
mp3gain has a lot of options that you’ll need to look into. Depending on your level of audio perfectionism, there may be one or two there that warrant attention.