When I add my own music to a stage, the music is too quiet and is often drowned out by the other sounds. But when I am at a title screen or character select screen, the music sounds fine. I can not increase the volume of mp3s because then my title and char select music are too loud.

When I change the value of bgvolume in the stage's .def file, it seems to have no effect.

What can I do to fix the problem?

EDIT: Perhaps I need an mp3 plugin? How do I know if my screenpack has one?

Problem solved. I downloaded a different screenpack (EvE), and now I don't have that problem anymore.