I would get some good seated position measurements and dig out my old SPL meter. That room is the only issue you have.
You would be better off no matter the shape to add some type of mechanical sub/bass traps. (I use tunable tube traps).
That will fix the boom along with speaker placement. The higher frequencies are usually open flat surfaces that are untreated.
YOU have a room full of those. I would be using tube traps and mobile panels. Those goofy nooks and crannies is the only reason
for the SPL. It just gives me an idea of the collection points in the room. Several corners coming together will usually need
treatment, curtains or mobile panels. I really don't like the studio look AT ALL.
I'd spend my time on speaker placement, and my money on decoupling the speakers and room treatment first.
I have a shop sound system that I set up for around 1200.00. I was messing around and I posted the numbers
and where I spent my money on a forum 5-6 years ago. The equipment was OLD/new. I was proud of the fact
several of my picky a$$ buddies couldn't complain about a single thing in a back to back test against a reference
system at the other end of the shop. It was well over 80K. SR-1/Pass stereo system. One of the few speakers
I regret selling. SR-1.B with a ribbon mod on the top box.
I could tell a difference but I think more of it was in my head. The SR-1 can hold it's own anywhere you put it. One
of my favorite box speakers. But I was using some rebuilt Infinity RS4Bs that I paid 180.00 and they came with a
new surround kits. EBay special. They even paid the shipping. The Pass did have a lot better sub/bass with a CD source.
Not so much with a TT source and a rumble filter engaged. Close in reproduction. 35,000.00 vs 140.00 usd.
IT WAS THE ROOM, not the speakers. You can use panel exciters IF you take measurements and treat the room.
It's actually kind of fun with surround or multi channel panel exciters. They are for sound affects anyways. I
did a C45 that way 15 years ago.
Side note: I use two main speakers. I go by tonnage. About 400-500lb for each main. The other 1/2 ton is
for sub/bass reproduction. About a ton will do a real nice job. The older I get, a little more meat on the bone,
so to speak. By 75 I'll be up to a ton each on the mains.
My kids want the speakers, wait till they have to
move um when I'm gone. I'll get even. Kids.