I would start with room treatments first. Otherwise, you are simply trying to fight the laws of Physics (or acoustics, more accurately). Room modes, peaks, etc. will significantly degrade the performance of even the greatest components.
Have Rives Audio do a room analysis and design. Then, the sound from $5k system will be more accurate than a $20k system in an untreated room.
Have Rives Audio do a room analysis and design. Then, the sound from $5k system will be more accurate than a $20k system in an untreated room.