Well certainly a tall ceiling would help in this situation I believe. 9ft or 10ft. 8ft ceilings put the listers to close, causing uneven coverage unless this is a small HT with only a few seats. But I know you do a lot of big theatres with multiple rows. My mind immediately races to coaxials, for the same reason it often does for surrounds. But perhaps in the 8" rather than 10 or 12" sizes. I also immediately think of a heavy duty dome tweeter that can cross over to a 5" Peerless woofer at 1500hz if smoother response is desired. Something good in a 15L sealed box. And the box, that's the key to this whole thing I think. The box shape would be very shallow. And would have a baffle not much larger than the driver. Then it would have sloping sides at maybe 20 degrees that extend down (up) to the ceiling. This would allow the response to be quite free of diffraction, and also lack any baffle step issues (half space). The final dimensions would line up with joist spacing if fortunate enough. Difficult to construct certainly. The SPL goals are 6db lower than most are used to, so this is nice. And with the lack of baffle step losses and short listening distance, SPL certainly wouldn't be the focus. The focus is uniform and wide coverage.
Think desktop speaker goals with a little higher SPL requirement than that.
Last edited by tuxedocivic; 06-23-2014 at 11:49 AM.