[linux-audio-user] Removing voice

I'm running debian sid. Anyone know of a good filter I can use to remove voice? I've got some flac files that I'd like to filter to remove voice and burn for my kids to sing with. I tried using xmms, which has a few voice removal plugins that work fine, but if I use the Disk Writer plugin for output then the effects are not in the output wav files. I tried using sox: sox in.wav out.wav band <center> But I can't find a good setting for <center> that works anywhere as well as xmms's Voice Removal or DeFX plugins. I'm looking for something like sox -- trying to avoid snd or audacity just to make converting a lot of files easier. Plus, I tried Steve Harris' LADSPA Karaoke plugin and it doesn't seem to work quite as well as the ones in xmms. Subjective, of course. Any suggestions? -- Bill Moseley moseley(a)hank.org