hmm i use dBpowerAMP Music Converter. it converts prettymuch ANYTHING. you DL the program, and if you wanna convert MP4, ram, wma, and prettymuch anythinggggg. i like this one cause you can just choose any mp3 or audio file and right click, and it gives you the options to convert to. you can change the bit rate, frequency, or even stereo/mono. quick and easy!!
you first DL the program and then DL the separate codecs
program:
http://www.dbpoweramp.com/dmc.htm
codecs:
http://www.dbpoweramp.com/codec-central.htm
it's a 30-day trial license so you gotta 'pay' after 30 days to continue to use.. i got this awhiiile back and i dont got the crack anymore but you could probably find one on google. my badd