Hi,

It's complex. If the distance between the various woofers is large enough they may excite different room modes differently.

Let us take an example. We place two subwoofers, one in the left front corner and one in the right front corner, driven MONO!.

We have just killed one main room mode and odd multiles, namely tose where the pressure in the two corners would be opposite. We can now add two more subs (which can be quite small as we have so many) in the other two room corners and voila, some more room modes killed.

The next step is of course to add for more subs in ceiling corners, now the only room modes that can be excited are those that require the two opposite walls to be at the same polarity of pressure. We can no start seeking a listening position that places the listener just halveway between the nearest wall and a point where the remaining room modes of concern have co-inciding null points.

We will now have generated a very even, room-mode unaffected LF reproduction without requiring EQ, heavy duty room treatment or any such trickery, in theory anyway, reality usually throws some spanners into the works.

Still, I would suspect that swapping one single monster sub for cormer 8 sub cubes using an 8" Sub driver (ApexJr Super Sub?) with one suitable big amp will give a major improvement in bass quality, if only it was not such an absolute drag to implement in a normal house.... 

Ciao T