'goes in an apt. 12/7 wide--L-shapped room... a motorised screen ... 100inches in the middle 'tween the speakers---AND---the exit is in the left corner...Methinks you could accommodate a medium-sized horn (have to use corner on one side & part of the opening on the other), but that's just me. Problem is, all horns with a useful (low )extension are largish in diametre. Cain& cain, or the ORIS (excellent horn: www.diy-systems.com) are still mostly just under 2' diametre each...
But you'll be happy with the sound, even with HT!