I'm looking for some software to increase the volume of a track that I have in m4a (but I know how to convert it to whatever) for osx. Can anyone name such a thing?
I tried macMP3gain but that doesn't seem to help at all.
Try Audacity. It's an open-source cross-platform audio editor. I haven't used it for years, but normalizing a signal or at least amplifying it is one of the most basic things you can do. There ought to be a very accessible feature in Audacity to do it.