That is a big room, you got anything smaller, you can treat without getting the partner upset? Does it have to be that room? There is no fix without room treatment of some kind, or just use part of the room, Can you use partitions? Fold out while in use and back when not. Servo bass? OB servo bass, pressures the room a whole different way. If I had a room that big, there would be at least a 1000 lb of speakers, just for the mains and another 1000 pounds for bass units. That put it in better perspective...BIG room, BIG speakers, more work...
Regards
Regards