I'll try to explain the situation: my room is L-shaped. I sit along the "bottom" wall, looking "up" into the L. The speakers are placed 5-6 ft from the rear wall( "top of the L"), and 1-1.5 ft from the sidewalls. The free spaces for sub(s) is along the sidewalls just behind the speakers. I've made a sketch, but I don't know how to post it. XO would be around 50Hz 18 or 24 dB/oct.