[Sonnie]

Generally if you optimize for several locations... all locations sacrifice a little, some more than others. But it is still difficult to optimize for anywhere in the room. It would probably take several precisely placed subs to accomplish it.

I installed an inexpensive Infinity system with one of those smaller subs in a big house once. Similar setup... cathedral ceilings... big open room. It sounded rather good, but it was 30Hz and up. It would have probably surprised a lot of people because it wasn't very accurate. Quite a few people like inaccurate bass. When they listen to accurate bass, they think something is missing until they get use to listening to it. I'm pretty sure if you measured the response on that 6.5 subwoofer system, you'd find the response rolls off very rapidly below 30Hz. You are "hearing", but missing a lot of the "feel" part of it. I imagine a properly calibrated quality sub would be very different in that same room.