I recently bought an Onkyo 898 and am running NHT SB-1's all around for 5.1 with a Paradigm PS1000 sub. I want to add the two rear surrounds but the couch is against the rear wall. Adding two more of the NHTs won't work as there is a window behind us and they would be far too big. There is room above the window for relatively small speakers. I am wondering if it would be beneficial or I am out of luck due to the seating position? Are they any small speakers that might work, angled form the ceiling perhaps?