Waterford School Concert Hall
This 710-seat hall was designed and built to support the music program for a private (kindergarten through 12th grade) school, as a part of an Art & Performance addition to the school. The project also included choir and instrumental music rehearsal rooms, dance studio, individual practice rooms, a black box theater, stage shop, and administrative offices.
The construction consists of an outer CMU/face brick shell, with insulated steel roof deck. There is a small amount of the CMU wall surface exposed in the hall, (less than 5% of total surface). The remaining wall and ceiling surfaces are of multiple layers of 5/8” laminated gypsum board, (2 to 4 layers) in an effort to maintain low frequency reverberation. The site has no significant external noise impact problems, which made it unnecessary to design for high levels of isolation in the exterior shell, hence the lightweight roof structure.
The design of the HVAC system was carefully monitored to assure low delivery velocities, under 400 FPM. HVAC machinery is in a basement level mechanical room, located more than 100 feet to the west of the concert hall. The resulting background level is NC-20.
A dedicated speech reinforcement system is provided, utilizing one each of EAW ASR 690 and 660 speaker cabinets, situated behind the grill above the stage. “Effects” speakers, hung at the far left and right of the stage, were later added by the owner.
The gypsum board construction made it comparatively easy to construct the various multi-faceted wall and ceiling panels, which have provided a very effective degree of diffusion in the space. All of these panels incorporate (3) layers of gypsum board.
The hall was designed to accommodate a wide range of musical genre, anticipating a range from classical choir and orchestra, to occasional student rock bands. Approximately 2000 sq. ft. of double layered 18 oz. velour drapes are hung along the upper side and rear walls, which can be fully retracted into pockets. When in place, the drapes are spaced approximately 3-6 inches from the wall. A roller/ winch system, powered by electric motors in the attic operates the drapes, with controls in the stage left wings. The curtains are operated in groups of two, providing a large possibility for subtle changes in the reflection patterns in the room.
The measured average reverberation time has a range of 2.28 seconds when the wall surfaces are fully exposed, and is reduced to 1.53 seconds with the drapes fully extended.
The sound of the room is quite live with the walls fully exposed, lending excellent support for traditional choir music and classical orchestra. In the front seats, the first reflections are more apparent from the side walls. Further to the rear, overhead reflections become more dominant.
With the curtains fully exposed, there is a marked change in the room’s character, resulting in increased clarity, more appropriate for “modern” music.