- Get the largest acoustically transparent screen as possible for the space available. Recognize that projectors may be too expensive today for such a large screen, but prices will eventually fall. I can change projectors, but not screens and false walls easily.
- Trade a perfect' expensive- for an 80% good' reasonably-priced solution
- Use the lessons learned from others
Accordingly, my plan (see attached floor plan) in no particular order (although I paid the most importance to the screen and seating) is as follows:
- Finished dimensions 28'5 long, 17' 11 wide, 8' 7-3/4 high
- Carpet on floor
- No lights in the ceiling, but sconces on the walls
- A 6 high stage in front of the screen
- According to Auralex Acoustics Inc., a 29' 10 room length delivers the most ideal frequency response between the possible dimensions listed' based on a similar plan
- Room sound isolation to be achieved through RC channels, two 5/8 drywall panels with Green Glue in between
- Mineral fiber between floor joists in ceiling? Not sure about this. (update 1/26/11: Installed R-19 in ceiling and R-13 in walls on advice of the Soundproofing Company. Was not expensive: Material cost ~$300. Seems like an entirely worthwhile thing to do based on its property to absorb low frequency bass)
- Auralex-recommended schedule consisting of S3PP ProPanels, S3CT corner traps and SpaceCouplers suspended from the ceiling as follows (from Auralex):
S3PP ProPanels should be spaced evenly throughout the available open wall space to reduce room ring and slap back. Panels should start between 2 and 3 feet up from the floor
Additional low frequency absorption can be gained by spacing the S3PP ProPanels off the walls 203 inches, creating an airgap behind the panels. This can be easily done using small wood blocks or something similar
S3CT Corner Traps should be mounted in the available upper corners to help smooth low frequency inconsistencies
SpaceCouplers could be suspended from the ceiling over the listening areas to break up first reflections and help widen the sweet spots
- Consider lower-cost, generic DIY alternatives for the above, if available
- 2.40 aspect ratio, flat, 187 diagonal, 172.8 wide, 72 high (update 1/21/11: Revising screen dimensions based on discussions with Chris Seymour of Seymour AV and others on this forum. Brand Screen Excellence acoustically transparent Craftsman screen, 1.0 gain, EN4K material with GripFix. I chose this over others for its DIY-friendliness and good performance/cost update 1/21/11 - this fabric is no longer available for DIY market. Now considering the Center Stage XD fabric
- Develop a 4-way masking system using the methods described on this forum
Audio: Use my existing B&W speaker system - 803 Matrix and HTM center channel, and 800 ASW subwoofer. Will need to purchase new surrounds and perhaps additional subs.
- Two rows of 4-each 18' and 25' away from screen. Distances established by using Carlton Bale's calculator for THX recommended distancesupdate 1/21/11: moved rows forward with smaller screen and gave more space at the rear
- Modify riser to function as a bass trap
- Will need 1100+ calibrated lumen projector eventually. May initially get the BenQ W6000 which is reasonably priced and has high output. May not use entire screen initially
- Anamorphic lens - most likely the Isco IIIs
- Maximize throw distance to reduce distortion, but aim for about 20 foot-lamberts on screen
Equipment rack in separate room
HVAC: This is one area that I am not sure how to handle sound isolation. HVAC registers will be above and behind the seats and returns will be on the left wall between the doors. I have a variable speed fan which is usually very quiet. Also, our basement tends to be a comfortable temperature and I don't forsee the heating/cooling being turned on. But, just to be safe, I did get the HVAC engineer to consider options for acoustics. He recommended a separate thermostat in the theater and a separate trunk line with automatic gates' for the theater. I am not sure how to prevent sound from the rest of the house/air handler from reaching the theater, and am not sure if this arrangement will provide sound isolation. He suggested a liner in the ducts that absorbs sound. The contractor's recommendation is, "Install two 12x6 high wall registers behind seating. Install a 16x16 low wall return air grille with a 10x8 return duct. The new supply air trunkline and return air riser duct are to be lined to reduce noise." update 1/21/11: Dennis Erskine gave great suggestions. Located supply and return registers up high. Supply at the front and return at the back near PJ. Pointed downwards, bar-type, 4"x48". Insulated flexible 8" ducts. Air flow = 340 CFM for 10 people+equipment. Capable of being zoned separately in the future. Air speed at registers kept below NC20 noise criteria 250 fps.
Any suggestions will be welcome. Thanks, all!
I walled off the curved space in the theater on the advice of Auralex. The curved space is especially difficult to treat acoustically. By walling it off, I can use it for my equipment rack