Normalcy with subs is to have one hidden box, placed out of sight regardless of optimal placement, that's tiny and not too loud, with furniture placed to better present the room, not the movie. On AVS, having multiple large furniture sized boxes optimally placed in the room, even to the extent of rearranging furniture to help placement (or get out of a null), with furniture worked in and orientated for optimal viewing and listening to a movie (not conversing with each other) is required before asking any questions about getting better sound or more out of a system.
Let's face it we're not normal here!
At my house I get the frequent question, "Why is the couch moved forward in the room from its normal spot?" I reply, "Well, I got tired of leaning forward on the edge of the couch for optimal greater depth of bass, so I moved the couch so I could lean back and relax while listening." Resulting in a shaking of the head in a disapproving fashion by the lady.
Only to be followed up the next day with, "Now why is the couch BACK in it's original spot?" To which I have to explain, "Well, I got tired of the mid and upper frequency interacion of the headrest of the couch so close to my ears when I was leaned back relaxing, I moved the couch back so I can lean forward on the edge and optimize imaging and clarity of vocals." Followed again by a rolling of her eyes and quickly walking off.