For 7.1, the side speakers should be placed at plus and minus 90 degrees; i.e., directly to the sides of the primary listening area, not behind the listening area. The rear speakers ahould be placed at about 150 degrees; i.e., spread out on the back wall away from the centerline.
From my own experience, 7.1 provides a much more enveloping surround environment than 5.1.
Regarding 6.1 sources, there are one discrete and two matrix formats. Notwithstanding this, the material should be played back on a 7.1 speaker array rather than a 6.1 speaker set up. One reason is to avoid the potential for back to front reversal if a single rear spealker is placed on the centerline. Another is it spreads out the rear channel information as the rear is not intended to be a point source like the front center channel.
Since ther are no 7.1 sources available, at least at this time (high def DVDs may include 7.1 audio tracks?), you need to apply some type of processing to either 5.1 or 6.1 sources to best enjoy a 7.1 setup.
Some Prepros simply replicate the suround information in both the side and rear channels, but I don't consider this very desireable.
Lexicon has long provided 7.1 processing with Logic7, and now DPLIIx is a viable alternative. In either case, these processes wil take the original surround information and redistribute that surround information across discrete side and rear speakers, generating stereo rears. For more details on exactly what happens, I suggest going to www.avsforum.com and looking for posts by sanjay.
Hope this helps,
Bruce
From my own experience, 7.1 provides a much more enveloping surround environment than 5.1.
Regarding 6.1 sources, there are one discrete and two matrix formats. Notwithstanding this, the material should be played back on a 7.1 speaker array rather than a 6.1 speaker set up. One reason is to avoid the potential for back to front reversal if a single rear spealker is placed on the centerline. Another is it spreads out the rear channel information as the rear is not intended to be a point source like the front center channel.
Since ther are no 7.1 sources available, at least at this time (high def DVDs may include 7.1 audio tracks?), you need to apply some type of processing to either 5.1 or 6.1 sources to best enjoy a 7.1 setup.
Some Prepros simply replicate the suround information in both the side and rear channels, but I don't consider this very desireable.
Lexicon has long provided 7.1 processing with Logic7, and now DPLIIx is a viable alternative. In either case, these processes wil take the original surround information and redistribute that surround information across discrete side and rear speakers, generating stereo rears. For more details on exactly what happens, I suggest going to www.avsforum.com and looking for posts by sanjay.
Hope this helps,
Bruce