I am setting up my 5.1 home theater in my basement and need some advice with rear speaker placement. The room is about 35' x 25' with the TV mounted on the longer wall. The area for the TV is 15' x 15'. Right now I have the center just below the TV and the right and left front speakers a little above the TV. Because the wall to the left of the TV is so far away I currently have the rear speakers mounted to the ceiling a little behind the seating area pointed down toward the seating area. Is this the best setup or should I mount them on the back wall which would be 8'-10' behind the seating area? There is one obstacle I have to worry about and that is the HVAC ducts that go down the area parallel to the TV. The speakers are behind this from the TV.
Thanks so much for your help.