Just noticed this thread and seems it has been quiet but will add my DIY Basement Theater. I started with an unfinished basement and added a section of wall and a door to seal the room. I built cabinets that extend back into a crawlspace to make better use of a small space. The room is just over 12 feet wide and a little under 18 feet long with ceilings just under 8 feet. I built a small Reiser for the back row of seats. The room is modest but the image is fantastic. It has total light control with dark walls, black at the front, and black velvet curtains on the front walls.
Main Theater 7.1.4 (3 Subs) - JVC DLA-RS3100 Projector, Panamorph DCR-J1 anamorphic lens, Stewart StudioTek 130 G4, 115” x 49” (125”), Lumagen Radiance Pro 4242, Marantz AV7705, Oppo BDP-203, Apple 4K TV, Infinity Prelude Compositions; Mains - Model P-FR (2 ea.), Center - P-CC, Surrounds - P-QPS (2 ea.), Heights – 4 ea. Cascade Model Three V, Rear Surround – 2 ea. NCM Okara II, TC Sounds LMS Ultra 5400 18" Subwoofer, 2 ea. LMS-R 15" subwoofers, Monolith 7x200 Amp, B & K REF 200.5 Amp, 2 ea. Crown CE4000 amps.

This is our family room system after a recent remodel. The amplifiers are in a cabinet I built in the crawl space below the family room.
Family Room – 2.2 system: Anthem STR Preamp, Bryston 6BSST, QSC PLD4.2, 2 ea. Dynaudio Contour 20, 2 ea. Scan-Speak 32W/4878T Revelator 13" Subwoofer’s, VPI Prime Turntable, Ortofon MC Cadenza Bronze Cartridge, Cambridge CXC CD Transport.
5.1 system-STR HT Bypass: Denon AVR-X6500H, LG 77 CX, 3rd Dynaudio Contour 20 for CC, 2 ea. Infinity Cascade Model Nine surrounds, Apple 4K TV, Panasonic DP-UB820, XG1v4.
