It occured to me that I didnt know the answers to these questions. I'm working on a film that we plan to mix in 5.1 and I have a few questions reguarding surround sound on a comp. Take a 5.1 soundcard and 5.1 comp speakers, does it work or do you need something else also? I remember seeing some sort of external dolby digital decoder box for computers thats why I ask. will 5.1 comp speakers convert stereo into something like pro logic or will it leave all the other speakers out of it? 5.1 video on a 2.1 comp system, what does it do downmix it to Stereo? IF so, will this sound worse or awkward opposed to an original Stereo source? That's a general question I've been asking myself today. Do DVDs that only give you a 5.1 option and no stereo still have a stereo mix in there that they keep for people without surround sound or does it always take the Dolby Digital track and downmix it to Stereo? And once again, does this sound...weird compared to an original Stereo source? Thanks for any help.