My wife and I are moving into a larger home with a huge great room. The room measures appx 18' front to back and 40' left to right. The ceiling height is appx 15' +. It was formerly a garage turned into a great room with the ceiling taken up to the roof. I'm envisioning a large home theater/stereo setup which would use a build out off the wall over a large section to house the drivers and their airspace and provide plenty of baffle space all while keeping a more integrated look (no speakers sitting on the floor anywhere).
Because of the size of the room and my intrigue by them, I wanted to give the Bohlender Graebener RD75 a shot. They could be built into the wall in sealed cabinets and with plenty of baffle space to provide better low end response and then be mated up to a large woofer to carry the rest of the low end spectrum. Through reading, most users have recommended a 300-400hz crossover point for the RD75 when used sealed (instead of dipole) to limit the low frequency extension and distortion. I'd like to implement a 2-way using active processing (DCX2496 and DEQ2496) so I'm looking at options for the low frequency driver. The RSS390HF seems like it may be a decent candidate with its low Le and low overall distortion design, decent sensitivity and low Fs with good xmax. It looks like the response is good with breakup past 1K so a crossover point 2 octaves below that with 2nd or higher order slope sounds like a good workable option. In a room that size, would one RSS390HF for each side be enough to play with serious authority for music and movies or would I need to consider 2 per side? I'm also assuming I would want to keep them low to the floor to couple for increased output?
With all of the space available and the mounting dimensions, I could have a 12" build out off the wall that is as large as needed to house the enclosure volume and have the projector screen cover a large portion of it as well with grill covers for nicer aesthetics.
Thoughts on the RSS390HF or any other options that might be better suited?