I have a similar difficult room and have solved the issue with Tyler Woodmeres go to the website and look at the speaker, Bass drivers top and bottom, mid and treble array at ear level these speakers will solve your large room needs without taking up much floorspace....
Which speakers will fill 5,000 cubic ft coherently
In porevious threads I've bemoaned the fact that my Kharma 3.2 FEs don't fill the room, 17 X 23 X 15 ft ceilings with a vertical enough soundstage, as though the speakers are literally too small. I have been advised to raise them,which I have done, , I have told to get taller, line arrays, even given names of custom speaker makers. Any specic recommendations from those that have had, and have conquered, this issue.