And you know, Looking at the charts that Mike posted, the AV does model well. Throw in an 80hz lowpass filter, and you are nearly flat to about 22 to 23hz, and only down 2db at 20. Room gain should compensate there.
As for what I'm looking for, well, I just want a really good home theater experience. My room is about 700 square feet, but with 12 foot ceilings, and is open to the rest of the house on three sides - with big entrances and cutouts, so it is not ideal at all.
Left and right speakers were fitted with an 8" sub with 240 watt amps in each, and are leveled to match the speakers pretty well. It really fills in the low end nice - for left and right speakers that is, and is perfect for music, no other subs are required for music.
What I want is to turn on these extra subs for movies only. I wouldn't use them for music. Because of that, I want to be able to put in a movie, feel the explosions a bit, and not have to worry about coils getting too hot, or drivers bottoming out. That's why I'm thinking running two at modest levels would be better than running one to the max. I've always been the sort to double up on hardware, rather than run what I got to its limits.
So as I looked at the charts, and saw things in the 110 to 115 range for 20hz and up, I'm thinking that would be pretty good for the movie experience. Doubling up on it would be the extra impact I want, without the extra worry about exceeding the limits of the equipment. Like I said before, I don't want some intense explosion in the movie at some critical plot point disrupted by my amps clipping or my subs making funny noises.
I'm also not keen on reproducing some 5hz sounds that the Ironman movie may or may not contain. Everyone who watches a movie over my house are your regular run-of-the-mill movie goers. Put them in front of a 72" screen, and shake them a bit with the audio, and they are easily impressed and have a good home experience. So in a nutshell, that's my goal.
I'm not sure if I'm asking too much in this regard. Hopefully I'm on track.