Okay I got thei concert on dvd, I demuxed the dts sound and decoded it to 6 pcm files...

First of all whats a good format to put these into? I don't want to encode to something lossy, I already ahve the concert's ac3... no point in encoding the dts files into ac3. Nothing really supports 5.1 eh? Whats a good way to mix it down to 2 channels?

OH yea and I'm trying to play with these and i say they're 48000hz 16bit blah blah and they end up playing 2x speed. WTF?

Ogg Vorbis supports multichannel sound with up to 255 channels. But the multichannel-feature is not tuned at all yet so that there is no channel coupling...

AAC and WMA9 support multichannel even though I do not recommend them. If you're that much interested in multichannel sound try aac or keep the genuine AC3.

Use Besweet for en- and decoding multichannel files (it supports ogg, but i dunno if aac either). or headac3he might suit you.