Considering the entirety of this HT build is looking like it will be completed during (and thanks to) the COVID19 situation causing me to be working from home for 4 months I think it's only appropriate to update the name of this theatre to 'The Corona Theatre.' I'll find a nice minimalist crown design to paint somewhere in the room. It also works with the purple walls and the fact that my household is bilingual.
Anyway, it's been some time since my last HT build, and even longer since my first build using knowledge from this forum many years ago! But this time it's for real as I finally got myself a blank canvas (1800 sqft unfinished basement). I'll update this post here if anyone wants to chip in thoughts/tips or observations I may have missed. I do have a few questions that may warrant separate threads since I haven't finalized all of my gear decisions yet, but I'll summarize them below.
I've been framing, plumbing and wiring this basement for the past 3 months so I've had plenty of time to read in the forum in the interim and much has changed in the AV world since my last build! Shout out to three individuals in particular who have posted a wealth of great information over the years that has proven helpful for many of my design decisions:
• Theatre is 22'10" long, 14’4" wide and has 9' ceilings with a 7'7" height tray on the perimeter enclosing HVAC, structural beams, etc. I framed single non-staggered stud walls to maximize space.
• I used 450 IB-1 clips, 145 pieces of 10-foot hat channel, double 5/8" drywall, green glue, acoustic caulk is going in the cracks and outlet gaps, and MLV rolled in the gap between bottom plate and floor plate (It's a colorado thing). R20 stuffed in the ceiling throughout the theatre and open adjacent media hallway. (8) recessed LEDs are in airtight 4" cans.
• Adjacent hallway will house all physical media (150 square feet of wall shelving) and is soundproofed to the same spec as the main room
• 2x3' equipment closet in the left wall that will house a wall-mount rack
• I ran four circuits to the theatre off a 100A subpanel in the basement:
- 20A serving only the four corners of the room (prewire for active subwoofers)
- 20A home run in the closet for one passive sub amp
- 20A circuit serving another receptacle in the closet for the second sub amp as well as two projector duplex receptacles, and the riser receptacles, and
- 15A circuit serving a third duplex in the closet and the remaining duplex outlets in the theatre itself.
All lighting is on a separate circuit. I put a whole-home arrestor in the main service panel. Putting the four corners on a single 20A will end up being wasted effort since my plan has since switched from powered subs to passive subs with rackmount amps
• Will likely need to build a hush box as I recently discovered that due to living at 6,300ft I have to run the JVC in high altitude mode which is quite loud (58db) even on low lamp mode
• Rear riser at 14", will attempt to set this up as a bass trap. Front stage will be built at ~12" height
• 2 rows of 3 seats, 4-seat bartop behind back row
• Front minimal screen wall will be ~14” out from the finished wall and covered in black velvet
• 150-155” scope screen. Will shoot some images on the wall once drywall is in and narrow this down precisely. Aiming for money seat at 2x screen height
• Room is totally light controlled. We are rocking over the window in the back of the room, and will have blackout curtain on the inside of the door. Planning to mount the pj at 17' (4" beyond it's minimum distance for a 155" screen). Should be getting about 15fL on the screen. HDR is probably a no-go.
• Finish will likely be black carpet and deep purple walls, with black velvet on screen wall and on walls near front of theatre
• The last piece to go in will likely be a star ceiling on 2" foam
• Usage 85% movies, 10% music, 5% games
• (3) LCRs (14/4 speaker wire)
• (4) surrounds (12/2)
• (6) Atmos speakers (12/2) – middle row won’t be used initially
• (2) front wides (12/2) - won't be used until Denon's 13-channel amps get cheaper
• (6) subwoofer cables (14/4) - The four corners, with double cables for each of the front corners
• (4) subwoofer cables with RCA cable (one per corner)
• (4) Riser step lighting boxes
• (5) Riser receptacles (on a 20A circuit)
• Adjacent to front right seat I am building out a small "armrest" out of 1x6 wood that will sit just below the height of the actual armrest of the seat. Within that stub out are prewires for (2) HDMI, (1) Toslink, (1) Headphone jack, (1) Component Video, (1) RCA A/V, and (2) USB jacks.
• (2) projector ceiling outlets on a 20A circuit, at 15’ and 18’
• (2) projector CAT6 cables
• (7) additional empty 2.5” conduits with pull string: one behind the screen, three in the ceiling joists (one earmarked for star ceiling fiber), one at the projector, one by the left surround speaker, and one where the riser will meet the wall by the A/V closet
(in italics is not yet purchased but what I'm leaning towards)
• Projector: JVC X790R
• HDMI: Ruipro 8GBPS Fiber (15’)
• Screen: DIY 155” scope Seymour Center Stage XD AT screen
• Receiver: Denon X6700H
• Amp: Marantz MM7055 (LCRs only)
• Amp: Denon AVR-3803 (repurposed pre-outs as amplification for Atmos only)
• Subs: (4) LaVoce 21" (SAN214.50)
• Sub amps: (2) Behringer NX6000D
• Tuning: MiniDSP 2x4HD, UMIK-1, REW
• LCRs: Titan 615LX
• Surrounds: Klipsch R-5650-S II
• Surround backs: Klipsch R-3650-W II
• Atmos: RSL C34E
• Door: Simpson 4948 solid hickory 1.75” exterior door with IG glass
• Seating: Palliser Techno or Flicks (2 rows of 3)
• Rack: 29RU Middle Atlantic Slim 5
• Media: Panasonic DP-UB9000, Apple TV 4k, nVidia Shield, Playstation 5, and will be building an updated HTPC
• Raspberry Pi runs emulators, MAME arcade controls will be integrated into rear bartop
• Chief RPMA281 projector mount + Peerless EXT002 short drop tube (had to chop one end of this off since only one side was threaded). This allowed me to thread the Chief mount all the way into the ceiling mount plate.
1) Subwoofer configuration
- I am leaning towards shallow subs all around - such as one of the shallow 18's in the links below, as I could then put these behind the screen wall. For the rear I am considering building them into the riser to save more space, but realize this will be more difficult. Or I could fit three shallow 18s behind the screen wall and ditch rear subs altogether...
I went with four 21s in custom cabs, noted in a later post in this thread.
2) Screen Size
- Will be a scope screen (probably 2.40:1), but in my original design there was no screen wall so I was sitting 12' from the screen - this put the money seat 1 screen width from a 155" diagonal screen (143" wide). However, building the screen wall out 14" will put me at 136" - incidentally this is a around 2.25x screen height, as the screen will be 60" tall. This seems potentially too close, but I do like immersion. I'll know more once I have drywall up and can test some sizes but am I right in thinking that 'on paper' 2x screen height is a commonly used distance?
Went with Seymour XD material as planned, sized for 155" 2.40:1 screen.
3) Room Modes
- I believe I'm correct in assuming that as long as the screen wall I build is acoustically transparent that all of my seating distances that were carefully planned to eliminate nulls will still be good since the subs will "see" the room dimensions as being where the actual drywall is, not where the screen wall is? Front row is 54% of room length and row two is 82% back, pretty close to the ideal 55/80% marks. Width wise, I am placing the prime seat at 45% of room width (left aisle will be wider than right aisle as seats are shifted a few inches right). I am hoping that the combination of 2" foam on the ceiling (star ceiling) plus a riser acting as a bass trap will mean I need very little or no other room treatments except for possibly treating first reflections on the side walls...
Pictures of progress so far are below. Comments and suggestions on the above, or otherwise, are welcome.