Go ahead and I'll see if I can help. After all we are talking about bass management and some of this stuff can only be figured out by actually going through the process.
I've sold most of my EP subs but recently added some sealed subs to my HT so I am back to having a quad of subwoofers throughout the HT.
Here is an informative discussion by Ian on the topic of multiple subs. He goes through a good summary though I find getting the phase between multiple subs set up properly takes more effort than what is being suggested.
http://www.axiomaudio.com/videocenter.html 
