Once again, I would shrink the space and change the proportions. I would also re-allocate some money.
Seating on the back wall, in the back 2 corners is wasted money. The audio is going to outright suck in those
two seats so to me, they represent money best spent elsewhere.
I would be thinking stereo DIY Fusion 8 MTM, plus a dipole sub firing to the sides. Simple flat black spray finish.
I would use a multichannel avr. Two seats so they aren't on the walls. Seymour XD screen, with vertical masking
panels for scope images. I would treat for first reflection points, for the side walls and the ceiling.
Why stereo? With a close to 7' wide room your center channel is going to dead center at 3.5'. Now that is exactly
quarter the wavelength of 80 Hz wave (14' long) so with quarter wave cancelation, an 80 Hz crossover point won't
be a good start for a seamless sat/sub crossover. Put a stage there and you're going to be close vertically too. So
I'd recommend a receiver offers some alternativecrossover points that work with the speakers, if going multichannel.
I also find having a surround channel jump out of the mix spoils multichannel magic for me.
A 45x80" screen is so 2003....
Brings me back to my first projector, a Plus Piano HE-3200 with 848x600 resolution.
Really nice picture at 45x80", for dvds. 1:1 pixel mapping. So your existing pj should REALLY be up to the task for that
screen size. An XD AT screen and sliding upper and lower masking panels would maximise what you could pull off up
I would continue the "cheap but good theme" with speaker grill fabric walls. Total black cave. And stuff some seats with
a WOW factor in there. A three or four zone Lutron Grafic Eye lighting controller for some lighting WOW factor and zone
front and seating.A couple of conduits hidden in the soffit, for cabling runs and wiring for an infrared repeater system.
I expect two exits might be required, so I'd add a window in the entry area. MA Slim5 av rack or a used computer rack
I'd be looking to maximise the interior width in the theater section, so I have to wonder if strapping plus some low
expansion spray foam would work for the side walls.
It might be cool (or be overwhelming) to do some LED stripe lighting with fabric panels in a narrow room, and plant on
that lighting on the fourth zone of the Lutron.