Couple other notes...
Seating in the center of the room can be one of the worst places for your LP. 1/5 the way from the back wall can be good, as can somewhere
between 1/2 and 1/3. (Acoustics is tricky
)
Back to the subs: because your room is not completely regular in shape, the standard symmetrical model of opposing corners, 1/2 wall, 1/4 wall, and other such placements can start to break down. Using the Crawl to find the actual best sounding spots can be super helpful, and then with good room correction or use of a calibrated mic and measurement program like REW you can dial in specific best placement. As I said before, symmetry is not always advised.
Cheers!