It does exist. Going back two steps we had 5.1, which consists of 5 full range speakers (2 front mains, 1 front center channel and 2 rear surrounds) along with a low frequency effects channel (the .1). Most DVDs are encoded in either DTS 5.1 or Dolby Digital 5.1. More recent is 6.1 which adds a center rear, to make transitions more natural. More and more receivers are available with this, but not many movies. With 7.1 you have the three front speakers, two surrounds at about the same location as the listener and two rear surrounds. As far as I know (and I could be wrong) there are no 7.1 encoded movies yet, so the receiver has to decode it from 5.1 or 6.1 sources. I haven't heard it so I can't say whether it offers much of an improvement. I would assume that more will be available in the future, but who knows. Also keep in mind that as you add more speakers you need more real estate to fit those speakers.

check your reciever setup you might have the option to switch between 6.1 and 7.1 i have this option on my sony 995

Does anyone know how i can hook up my PS2 on my creative 7.1 sound system.