Another question, or just daydreaming for now.

My couch is 2 feet, puts head at 3 feet, from back wall.

I have a 4 1/2 foot central area I can install back speakers.

I have 2 unused on-wall m22's.

My logical options for back speakers are:
1) mount one of these in the middle for a 6.1 system.
2) mount 2 of these 4 foot apart for a 7.1 system.
3) purchase and mount 1 QS8 in the center for a 6.1 system.

I'm not sure of the effect of using direct radiators this close to the seating area for rear surrounds. Would need to purchase more speaker wire so I can try it out.