Stuffit? Can you post specific results?
Because normally its like this:
Though I guess stuffit could compress better if
MP3 [free public-domain corpus]
Sound Slimmer 1.04.001/5 (06.07.2005) 115,366,235
packMP3 1.0 (2012) Matthias Stirner 116,431,200
STUFFIT 188.8.131.52 (SITX) 'LZAri:5:28' 120,000,797
PAQ8pxd_v3 (24.02.12) -7 -ww PAQ crew- 127,725,875
ORIGINAL FILE 131,430,398
1) The mp3s have huge tags, maybe containing jpegs or bmps.
2) The compressed set includes duplicate files or fragments.
3) mp3s are not really mp3s at all
The solution for (2) is to process the data with srep first, though
packmp3 won't work after that (but packarc would).