Home Movie Theaters

While this theater was my dream, the 7-year project required the support and occasional manual labor from my wife, daughters, son-in-law and a couple of friends. I did consult with Roy Johnson of Green Mountain Audio a few times and want to thank him for his insights.

Other than those acknowledgments, the Geek Theater was my baby, costing around $90,000 once it was all said and done. I designed the room, specified and installed all of the equipment and furnishings. I also did all the interior work myself except for laying down the carpet. In the design of the theater, my first objective was to make the room as audio perfect as possible and secondly, make it a “rock and roll” movie theater room.

To accomplish the first objective, I created the largest room that I could fit into the area available at the back of my house. I used the guidelines in the “Master Handbook for Acoustics” to correctly size the room. I had a spreadsheet set up to check for all room resonances up to 300 Hz. The room turned out to be 23’ by 17.5’ for physical and audio reasons. I added extra sheetrock to the short ends to prevent standing sound waves. The room has two doors and one small window that is now completely covered from the inside, allowing me to achieve pitch black any time of day.

I used alternating 2 X 4 studs in a 6” wall to keep the sound I wanted in the room and the outside sounds out. The wall adjoining the house was kept separate and the room, although adjacent, is not physically attached to the house except through the roofing structure. This minimized the audio feed back into the rest of the house. I used trim boards to mask the gap so that from outside the house it looks like the new addition is part of the house. I have 6” insulation in the walls and under the floor with a 12” layer of insulation in the attic space. This isolation/insulation is very effective so the room can be used at any time without affecting the neighbors or any one else at home. I also installed solid wood double doors (not side by side) at each doorway to stop sound migration.

The next step was to determine the interior layout. I followed Green Mountain Audio’s speaker location recommendation, which required a lot of floor space. Next, I found the seats and projector I wanted plus I picked the biggest screen possible based on the speaker locations, which in turn dictated the location of the seats.

I had Auralex use their software (I faxed them the exact room layout with speakers, doors, windows, etc.) to design the acoustic treatments for the room and followed their installation instructions as close as possible (one of their diffusers is on a door). I also suspended from the ceiling a 2” thick matte black acoustic panel for sound absorption. Additionally, I used a very thick pad and thick plush carpet for the flooring.

Since the projector is such a monster (size and weight) I custom built a special wooden support box for it. The box is attached directly to the roofing joists and was installed before the sheetrock was put up. The box has openings to route the cables from above the ceiling tile down through the box directly to the projector.

Perhaps, the most unique feature I designed into this room is the addition of a second floor on top of the standard floor. This second floor is made from 2 X 4’s on 16” centers glued top and bottom to the main and 2nd floor ” OBX flooring. Extra flooring joists were installed under the front and rear speakers to minimize floor vibration.

The second floor allowed me to do two unique things. First I placed 2’ X 2’ concrete pedestals under each of the 7 primary speakers (not for the side surrounds). This deadens feedback between the speakers through direct floor vibration. Secondly, I was able to build a seating platform. The nine theater-style seats were mounted on an 8’ X 8’ platform that is rested on top of rubber feet. Additional 2 X 4’s were mounted to the platform to allow bolting the theater seats firmly in place. Eight "shakers" are mounted from below on the bottom of the platform with four of them between each row of seats. The shakers are driven by a separate amp that can be adjusted independently of the bass for maximum effect.

The system amps are on the floor behind the front speakers (out of sight). This keeps the heat they generate from affecting any of the other equipment. I have a total of 5100 watts of power in this room. While I will never use all of that power, my philosophy has always been to get an amp with the maximum power the speaker can handle to improve the speaker's dynamic response and improve the overall sound quality.

One item that really helped the low frequency sound was the Velodyne SMS-1 equalizer. It really smoothed out the bass frequencies. It also has three outputs which is perfect for what I needed. I love bass and can really shake the room (without the bass shakers) when desired.

Using Stereophile test CD’s for test signals across the entire hearing range I have less than +/- 2 dba variability at 80 dba between 20 and 10k hertz (one +3 db spike at 50 hz. The sound level starts dropping off at 12.5 khz down to 70 db at 20khz. I can shake glasses in the cup holders when the T-Rex escapes through the fence in “Jurassic Park”. The quality of the sound and movie experience has exceeded all of my expectations. I thought the 5.1 surround format was great but the 7.1 format really makes the “room disappear”.

This is the ultimate dream for me. I hope that you are now inspired to build you dream theater, too.

EQUIPMENT LIST
AMPS
• EARTHQUAKE CINENOVA GRAND 3 CHANNEL AMP
• PARASOUND 2250 2 CHANNEL AMP
• NAD C272 2 CHANNEL AMP
• DAYTON 1000 WATT SUBWOOFER AMP (HPSA1000 FOR SHAKERS ONLY)
AUDIO FURNISHINGS
• 26 CLARK SYNTHESIS TI-100 NATURAL RUBBER FEET
• AURALEX SONOSUEDE HT SYSTEM WITH 4 BASS TRAPS AND 8 ABSORPTION PANELS • AURALEX SCREEN6 SYSTEM WITH 6 SPACECOUPLER PANELS
• ACOUSTICAL SOLUTIONS 2” ALPHA MIDNIGHT CEILING TILE
• RTI CORP T2+ REMOTE CONTROLLER
• DA-LITE 9’ CINEMA CONTOUR SCREEN
• NINE MOVIE THEATER SEATS
SPEAKERS
• TWO 18” VELODYNE 1200 WATT SUBWOOFERS
• GREEN MOUNTAIN AUDIO CENTER C2.0 SPEAKER
• GREEN MOUNTAIN AUDIO FRONT L & R CALYPSO’S
• GREEN MOUNTAIN AUDIO REAR L & R C1.5 SURROUNDS
• GREEN MOUNTAIN AUDIO EUROPA SIDE SURROUNDS
• 8 AURA SOUND PRO BASS SHAKERS
ELECTRONICS
• SONY VPL-VW100 1080P PROJECTOR
• PIONEER ELITE CD/SACD PLAYER DV-59AVi
• BANG & OLAFSON BEOGRAM 4002 TURNTABLE WITH MMC 5000 CARTRIDGE
• PIONEER ELITE BDP-09FD BLU-RAY PLAYER
• INTEGRA DHC-9.9 PRE/PRO
• MONSTER POWER HTS5000 REFERENCE POWER CENTER
• VELODYNE DIGITAL EQUALIZER SMS-1
• MARIGO LAB SIGNATURE 3-D STABILIZER V2 DISC
• WALKER AUDIO ULTRA VIVID