Your present room isn't all that big - about 1900 cu ft.

My HT room is about 2450 cu ft but is really irregularly shaped - essentially my system fires across the room at a 45 degree angle due to it being in a bay window well. I don't get any nulls in my listening area & I attribute that to pretty good performance.

I need to update my gallery pics so you can visualize what I'm talking about...

TAM