Wall behind speakers

I am remodeling a family room there are going to be 2 walls of windows (behind the speakers and right wall). I suspect there will be an acoustic difference whether the wall behind the speakers is flat or has an irregular (prow) shape or is on an angle. I will deal with bass traps after construction is done but suspect a flat (90 degree to side walls) will be more predictable. Any suggestions?
thanks in advance
yurkot