I recently realized my iTunes library (40GB+) has several albums/songs which are in bad need of audio level adjustment, since they come mostly from ripping my own CDs, but some were purchased on iTunes. Others still I had ripped from vinyl and tapes by a company, since I did not have the equipment to do that at the time (and this was waaaay before iTunes et al even existed). So, I reckon I need to batch normalize my library, since iTunes itself does a bad job with this. Idea would be to have this software run through a backup copy of the library, normalize each file's audio, and resave it under the same filename. I've seen Sox, but I'm not really sure it would be able to do something like this. Any suggestions?