Roughing It Page 2
SM: Sound isolation was accomplished by floating the theater space from the shell's outer walls. The floor was raised to accommodate tubing for radiant heat. This isolated the speakers from the concrete floor. The side walls are toed in from the rear wall to the screen wall, while the outer-shell walls are parallel. The ceiling is comprised of tongue-and-groove paneling that is suspended from the ceiling joists using what is called a "hat" channel. The client also designed the house so that there are no bedrooms adjacent to the theater. Even if a little sound does leak out, it would have to travel quite a way to disturb anyone sleeping in a guest room.
UAV: How was the equalization and system tuning performed?
SM: Each and every audio channel is supported by a Klark Teknik DN410B parametric equalizer. I then analyzed and flattened the response of each audio channel using a pink-noise generator and real-time analyzer.
UAV: How are the surround speakers configured, and how effective is the sound distribution? Too many surrounds in a small room may cause uneven response due to comb filtering, which is one reason why THX promotes the dipole surround.
SM: I actually used six surrounds. Since a portion of our allotted space was turned into the projection booth and the speaker/amplifier room, the length of the viewing space was shortened, so I eliminated one pair of side speakers [that were originally in the plans]. Because we still had three rows of seating, and each row is about 8' apart (six-foot-long chaise lounges instead of chairs), we still had quite a bit of surround "depth" to address. Therefore we employed a rear and two side speakers on each side of the room.
UAV: Is there any acoustic treatment in the room?
SM: Unfortunately, the budget did not allow for acoustic treatment of the whole room. We were able to place an acoustically absorbent material across the speaker/screen wall to eliminate first-surface reflections and help to eliminate the "slap-back" of sound reflecting from the rear wall. We also stretched an acoustically transparent fabric across the speaker wall to hide the left and right speaker stack and subs, as well as to give the wall a finished appearance.
UAV: Any other specific problems that were solved in the construction/installation phase?
SM: Because of the ample shell space, we were able to solve a number of problems without impacting or compromising the viewing space. The projection booth allowed us to isolate the loud and hot DLP projector from the viewing room. We were also able to inset the equipment rack within the wall separating the booth from the viewing room. This gives both the user and the installer easy access to the front and rear of the equipment as needed. We were also able to carve out a small "walk-in" closet at the back of the room in which the client was able to build shelving to solve his media-storage issues.
The speaker/amp room behind the screen wall allowed us to load the speakers into the wall from behind. The cabinets that house the front speakers and subs were then closed from behind, allowing the sound to launch quite nicely into the room. The amplifiers are racked up in close proximity to the speakers, allowing for shorter speaker-wire runs. The speakers and subs can be serviced without dismantling the screen or screen wall. We were also able to run copious amounts of conduit under the raised floor to connect the projection booth to the amplifier room. This will allow us to add any new technologies without having to rip up any floors, walls, etc.
TJN Comments: I'm not a proponent of overly large screens for video projection, but one person's "too big" is another's "just right!" Nevertheless, those contemplating screens of this size must insure that the projector will put out enough light for a sufficiently bright, evenly lit image (a screen with moderate gain, such as the Stewart Studiotek 130, might be desirable in such a situation). A perforated screen (which also sacrifices brightness) must also be chosen carefully when used with a fixed-pixel projector to avoid interference patterns between the pixels and perforations, resulting in moiré patterns.
If you only have one or two rows of seats, keep in mind that you can get the same impact with a smaller screen by sitting closer. This will avert issues like reduced brightness and a possibly soft look to standard-definition sources. The latter is caused by over-magnification of the low-resolution image, though if you're seated far enough from the screen you may not notice it. In this installation, however, with the back row of seats over 30 feet from the screen, the only way to provide the impact that the owner desired for all viewers was to use a high-output projector and a very large screen—something that would have been impossible just a few years ago when CRTs were the only option.
I hasten to add that I have not traveled to the far north to audition this system personally, so can only comment from the information and photos you see here. It's possible that adding some carefully positioned absorbers and diffusers in a future upgrade, plus extending the black of the screen wall a few feet along the sides to minimize colored reflections back onto the screen from the dark but non-neutral side walls, might further enhance the presentation. But it's clear from the testimonial we received that the owner is delighted with the current system. In the end, that's what really matters.