Home Theater of the Month: The Coffin Build

This gorgeous theater is the focal point around which the entire house was built, and it might just be the owner’s final resting place.

To realize their home-theater dreams, most AV aficionados adapt an existing room or perhaps add a new room to an existing house. But AVS Forum member Cory (doublewing11) took a different approach. “I literally designed the entire house around the theater space so it would be adjacent to the kitchen and dining room in order to enhance the entertainment possibilities.”

Performance was also paramount. “I wanted a noise floor close to NC 20 [the ambient noise level in a typical recording studio] along with acoustical excellence and the ability to contain low-frequency energy.” After two and a half years of planning and researching on AVS Forum—”and traveling up and down the West Coast from San Diego to Seattle listening to all kinds of home-theater gear, especially speakers”—Cory had The Erskine Group design the room layout, but he did most of the construction work himself.


Before construction of the house could begin, a huge retaining wall had to be built. The footing was four feet wide and two feet deep, and it required $24,000 worth of cement.

“I’ve built three homes with my own hands, but with this one, I only built the theater room and master bath with the help of a friend. It took us five and a half months—while I was working two jobs, I might add, which was no picnic!”


Here’s a view of the retaining wall from the neighbors’ yard. That thing is ginormous!

The construction is top-notch all the way. “I used 2×6 framing on all four walls with RC-24 insulation. The walls are 5/8″ OSB [oriented strand board] and 5/8″ drywall sandwiched with Green Glue and isolated from the frame with clips and channels.” Also on the walls are acoustic treatments from Quest Acoustic Interiors as spec’d by The Erskine Group, covered with acoustically transparent fabric from Gilford of Maine.


The Erskine Group spec’d Quest acoustical treatments on the walls.

Outside of the theater, dual-layer 5/8″ drywall was used in walls adjacent to the garage, kitchen, half bath, foyer, and dining room to lower the noise floor and keep sound out of the rest of the house. The noise floor has been measured around NC 25, and no sound from the theater can be heard in the kitchen.

“The foundation of the house is a crawl space, and the subfloor of the theater is isolated from rest of the house. I used heavy-duty TJI joists in the theater floor at 16″ apart rather than the more conventional 24″ because there is 3000 pounds of sand in the front stage. The floor itself consists of an 1-1/8″ layer of plywood, a 3/8″ Serenity Mat, and two layers of 3/4” plywood sandwiched with Green Glue. Floating floors are wonderful! Who needs butt kickers? The theater room rocks like a San Fernando earthquake, but rest of home is steady as a rock.

“The ceiling also has channels 16” apart to support the weight of the projector, soffits, overhead speakers, and ceiling cloud.” Fortunately, his family is in the lumber business, which made it easy to get all the wood he needed.

The home’s HVAC (heating, ventilation, air conditioning) system is equally well planned. “It’s a four-zone system with one zone dedicated to the theater, and it was engineered with total isolation of the supply and return to and from the theater room. Also, the returns in the theater are in the second-row columns, which are six inches deeper than the front-row columns; the wood registers effectively disappear.” Very clever…


Here, Cory installs 6 mil poly over the first layer of 1″ Linacoustic RC lining the front stage. Another layer of 1″ Linacoustic RC would be applied over that.

Cory refers to the work up to this point as Phase I, which began in January 2012 and ended six months later, one day before the house was opened to a “Home Tour” in the town of Dallas, OR. Phase II began the following summer. “It was originally planned to be a six-bay coffered ceiling, but it morphed into a “cloud” to hide overhead speakers for Dolby Atmos. AVS Forum members, especially Roger Dressler [whose Deadwood Cinema was featured as Home Theater of the Month in January 2015], helped design the cloud. With Roger’s help, I’m confident that my speaker locations, angles, and distances are perfect.”

The ceiling is divided into two large bays framed in knotty alder wood, each measuring 6.5 x 8 feet and 8.25″ deep. The front section has four inches of Owens Corning 703 and one inch of Linacoustic RC to act as a bass trap and first ceiling-reflection absorber, and it has mounting hardware and wiring for two overhead speakers. The rear section has four Viscoustic 3D diffusors as well as mounting hardware and wiring for four more overhead speakers. Both sections are covered with Gilford of Main Sensa acoustically transparent fabric.


The rear section of the ceiling has Viscoustic 3D diffusors that are normally hidden by acoustically transparent fabric.

As for speakers, The Erskine Group recommended Triad Gold LCRs for the front three channels and Triad Silver LCRs for the surrounds, with two pairs of side surrounds and a pair of rear surrounds for a 7.1 system with four subs. Cory hasn’t made the final selection for overhead speakers, which need to have wide dispersion and fit in the 8.25″ depth of the ceiling bays. He’s planning to visit Roger Dressler to hear the Tannoy Di6 DC overhead speakers, though he’s also hopeful that Triad might make a suitable speaker in the near future.


Three Triad Gold LCR speakers are placed behind an acoustically transparent screen.

Cory originally planned to use two JTR S2 subwoofers—he even bought one to see if he liked it. “But then I started reading the DIY subwoofer forums on AVS Forum and thought why not build subs on my own? I have woodworking skills and I wanted to dig deeper into acoustical science. So I sold JTR S2 and started down the road building my own. I stumbled upon a group-buy opportunity in the DIY forum to purchase IST UXL-18 drivers at a discounted price, and modeling them with WinISD software indicated that four UXL-18 subs would meet my goal of having reference bass down to single digits—i.e., 115 dB down to 7-8 Hz.”


Cory built four subwoofer cabinets using kits from the DIY Sound Group.

The current pre/pro, a Marantz AV8801, is great, but Cory will swap it out for a pre/pro with HDMI 2.0 and HDCP 2.2, a must for most UHD content including the upcoming Ultra HD Blu-rays. Meanwhile, he’s enjoying his Sony VPL-VW1100ES 4K projector firing onto a 2.37:1 Seymour-Screen Excellence Enlightor 4K screen. “I use zooming rather than an anamorphic lens. That projector throws an absolutely stunning picture—it was the best purchase for my theater!”

The biggest challenge? “Sleep! During Phase I, I was getting up at 5 AM, working until 11 PM, seven days a week for five and a half months. Researching the project for over two years set the path for smooth sailing, though having a construction calendar was helpful with such a tight timetable.” What about the greatest moment in the process? “Sitting down, relaxing, and enjoying the first family get-together watching Skyfall. The event was interesting, as my 87-year-old mother-in-law thought she had gone to hell and back. I guess she didn’t like the movie, but I thought it was fantastic!”


In this shot, you can see the beautiful knotty alder trim in the ceiling; this design element is used throughout the theater.

Cory estimates the total construction cost around $36,000, which is primarily materials since he provided most of the labor himself. AV equipment, control system, and furniture is currently somewhere north of $70,000, and that figure will climb when he installs a full Atmos system with new pre/pro and speakers.

That’s some serious coin—not to mention all the sweat and lost sleep—but it was definitely worth it. “There is nothing better than having a dedicated theater room next to the kitchen and dining room with it’s own dedicated half bath! The transition from dining to theater room is the best part of the design!”


The equipment rack is just outside the theater and next to a half bath, which is mighty convenient.

This theater does not have an official name, but in its build thread on AVS Forum, it is called the Coffin Build. “I know, not a catchy name, but as I near retirement, my son has referred to this room as my coffin. As he has said many times, ‘Might as well seal the door and call it your coffin.’ Seems fitting…” Indeed, I can think of many much worse ways to go.


Seven Front Row theater seats from Row One provide the ultimate in comfort.

For much more detail about how Cory’s home theater came together, check out the build thread here.

If you’d like your home theater considered for HT of the Month, PM or e-mail me with the details and a link to your build thread if available.

EQUIPMENT LIST

Sources

Oppo BDP-103 Blu-ray player
Dish Hopper satellite receiver/DVR
Sony FMP-X1 4K server

AV Electronics

Marantz AV8801 pre/pro
Parasound A 31 3-channel amp for LCR
Krell S-1500/7 7-channel amp for surrounds
ATI AT1807 7-channel amp for surrounds
Peavey IPR2 7500 2-channel amp for subs
MiniDSP OpenDRC EQ for subs

Projector

Sony VPL-VW1100ES

Screen

Seymour-Screen Excellence Enlightor 4K (144″ wide, 2.37:1, 1.0 gain, acoustically transparent woven)

Speakers

Triad Gold LCR (3, LCR)
Triad Silver LCR (6, surrounds)
DIY UXL-18 subs (4)

Cables

Blue Jean XLR interconnects
Monoprice 12 AWG speaker wire, banana plugs
Parts Express 12 AWG 4-conductor speaker wire for subs

Control

Savant
Lutron Grafik Eye (6-zone)

Power Treatment

Panamax MB1500 UPS

Seating

Row One Front Row (7 in 2 rows)