so if those aliasing effects are going to help, then maybe a big step will be to ADD aliasing.  there are a couple of suggestions here:

http://www.music.columbia.edu/pipermail/music-dsp/2002-March/047953.html

and here:

http://www.music.columbia.edu/pipermail/music-dsp/2002-March/047966.html

i'll give them a go tomorrow.