Originally Posted by JimP
I've been in audioguy's home theater and am trying to remember his layout. It seems though that although his subs are symmetrically in his room, they're not symmetric to his listening position. Won't that make a difference?
The front two subs are the same distance from the LP (hence symmetrical) and the rear two are the same distance from the LP (hence symmetrical). But the front two are further away than the back two -- which was set up that way to get flat uncorrected room response.
The reason the SubEQ works better than the 80.1 approach is that is takes into consideration the flatness of response Mark got by NOT treating the front two subs as an entity nor the back two subs as an entity. The pre-correction response of either of those two sets was ANYTHING but flat.
Again, the SubEQ does exactly what Mark wanted me to do: Delay the rear subs so the arrival time is the same as the front subs and set the output of the rear subs the same as the front subs. (I had done that before the SubEQ with the DSP30). Then it treats all four subs ans one and does its thing.
By the way, it is my understanding from Audyssey that the SVS Bass EQ version does NOT do it that way. It does it like the 80.1. That approach totally eliminates the effort taken to get the best FR without EQ.