Originally Posted by batpig
how can you EQ each speaker independently using Audyssey with this arrangement?
channels don't benefit from Audyssey. I am, however, using matching speakers (with the exception of a dipole pair), so the only inaccuracies would be due to their different placements in the room. The 5 rear channels are calibrated first (for distance and levels), then the the main receiver does everything else (that way, any coloration or processing delays from the secondary receiver should be accounted for).
if I understand correctly, you are then converting into 5 channels "upstream" using an external processor to apply PLII to the two surrounds. So you get one extra speaker (versus using PLIIx to turn 2 surround channels into 4) but you have to use an extra piece of equipment, and you can't EQ the channels independently.
Not quite... I have the standard 7.1 setup. BUT, the two rear channels are fed through a 5.1 PLII receiver (but no sub attached to it). So everything that my 7.1 receiver outputs goes to the same place that it would with a standard 7.1 setup, EXCEPT that some sounds directed to the two rear channels get re-directed to some additional rear speakers (3 extras). So effectively, it's 10.1.
But whatever works for you!
I can easily revert to "stock" 7.1 by just putting the "rear" receiver into stereo mode, but the extra DPL processing really does help in my "bad" room.
FYI - this is not actually accurate. They are not derived via the same sort of "matrix" processing that (for example) you can use to generate a center channel from stereo content (by steering "in phase" content from both channels to the center). Audyssey is adamant that their DSX processing is NOT the same as the standard matrix steering for, say, PLII. The "wide" channels are not just a simple "mixture" of the surrounds and fronts to create "in between" sounds.
Well, for that matter, PLII also isn't "simple" matrixing. But it is steering that is based on the phase differences and commonalities of various discreet channels. Audyssey can apply their own logic to it, but they still have to produce an end result that is similar. Because it's phase differences and commonalities that makes us perceive sounds coming from between speakers, or outside them. That's why movies (and even music) that was recorded before Dolby sound still worked relatively well once Dolby surround was invented. In a standard 5.1 recording, the sounds intended to be perceived as between the right surround and right front need to be in phase, because that is what makes our senses believe that's where they are. They can apply their own enhancements to it, but if they vere TOO far from that simple logic, they risk placing sounds in spots that perhaps weren't intended to be perceived from that spot. That's my take, anyway.