Dude!
That is a Large room in Bassaholic parlance... almost Extreme considering it sounds like the area is open to other spaces as well.
We could deep dive for another hour about set-up ideas, and how to maximize your room's acoustics without even getting into treatments... But I can't play like that right now. Suffice it to say, there is a lot of stuff that can be dug into, among which would be taking one of those subs and moving it closer to, and perhaps a little behind your seating area, provided your AVR can process each Sub individually.
A simple test would be setting up the Sub Crawl just to see where good positions in your room may be.