After toting subs around my room and taking many measurements, its time to post an update. Instead of posting to report significant progress, I feel less certain about everything.
On Monday night, I moved and stacked the P7S to the front right corner (next to the mains) and I moved one of the CSW 10 to the bump out next to the first row of seating while leaving the other one behind the 2nd row.
Here is the FR of the P7S stacked in the front corner
Here is the CSW10 next to the 1st row
Here is the other CSW10 behind the 2nd row
Here are all of the subs in the new positions without the mains
Here are all of the subs in the new positions with the mains
Here is the waterfall
Below 25hz was already lacking and then it dropped off even more. The higher frequencies did not trace the blue line as I'd expected. I began to wonder if I shouldn't have left the very heavy P7S boxes in place and instead moved the relatively light CSW10 boxes around first. I was too tired and decided I was done for the night.
Tonight, I decided to put the P7S boxes back in position flanking the center channel about 12 from the front wall with the drivers facing the front wall (its easier to reach the controls and all subs are sealed). I left the CSW10 in their new positions next to the 1st row and behind the 2nd row.
Here is a FR graph of the P7S back near its original position
Here is a graph of the P7S and the 1st row sub
Here are both CSW10 without the P7S
Here is a waterfall of all subs with mains
Here is a waterfall of all subs with mains (blue) with just the P7S back to its original position as an overlay (purple)
I'm not sure what to do next, but I'll try something tomorrow night. I have to be mindful of our desire not to see the subs as I crawl around looking for the sweet spots. I appreciate any thoughts and comments on the attached graphs.