By Russell Cooper, President, JaffeHolden, Norwalk, CT

Amarillo is a city of 230,000 and, until recently, was served by one multi-use performance hall: the Amarillo Civic Center Auditorium, in the city's Convention Center. With all of its 2,324 seats on one level, the proscenium-style auditorium was not a very inviting space, nor did it have very good acoustics. A new hall for the city, in order to be economically viable, needed to have 1,200 – 1,300 seats and also be multi-use. However it was the architect's vision not to design the typical multi-use hall with a stage house that works for theater, musical, and opera, but which is a compromise for music both acoustically and visually. Instead, Malcolm Holzman (of Holzman Moss Architecture) insisted on a "music room first" aesthetic, with the room adaptable for other uses: theatrically, acoustically, and architecturally.

Opened in January of this year, the Carol Bush Emeny Performance Hall in Amarillo's Globe-News Performing Arts Center is home to three performing groups—The Amarillo Symphony, The Lone Star Ballet, and The Amarillo Opera. While the emphasis is on live, unamplified music, Emeny Hall must accommodate amplified music as well, from rock to pop to Broadway-style musicals. But this venue is not like other multi-use halls. It features one of the most unusual acoustical designs in the world today, developed by JaffeHolden, in conjunction with Holzman Moss with theater design by Davis Crossfield Associates.

Traditional designs of the best concert halls in the world are one room, rectangular geometries, "shoe-box" shapes such as Boston Symphony Hall and the Musikvereinsaal in Vienna. The volume of these rooms is such that a symphony orchestra at full sforzando energy levels does not sound loud or harsh. Acoustically this means that the hall has to have sufficient volume for the sound of an orchestra to develop properly, sustain, and then decay naturally. The ideal volume to achieve the preferred great sound in these traditional concert halls is around 600,000 cubic feet. Symphony Hall and Musikvereinsaal seat 2,650 and 2,044, respectively. In order to maintain the necessary acoustic volume for a symphony orchestra to sound great in a hall whose seating count is 1,300 would require an extremely tall space which would have appeared and felt cavernous. The solution that the design team came up with was to use a room-within-a-room concept. The inner room would provide the architectural boundary of the space, thus providing the small theater feel of an intimate and warm and inviting space. The outer room, which would be acoustically coupled to the inner room through strategically placed openings, would provide the extra volume necessary for the proper acoustics.

Traditional vs. "shaper" design solutions
Since JaffeHolden is experienced in perfecting orchestra sound on the stage side for a multi-use hall through its "concert hall shaper" design, it was determined that we would employ this design for the Globe-Center project, but in a slightly different way. The shaper design uses a hard cap structure to seal off the upper stage loft area in order to keep sound from escaping into this large, absorptive space full of draperies and lights. This hard cap must then move out of the way when non-music performances are on stage using stage line sets.

The traditional approach is to use a series of portable towers and "tip and fly" ceiling panels. Setting the stage for orchestra concerts with this type of shell can take up to an hour with a crew of three to four people. The three or four ceiling panels live permanently on heavy counter-weighted or electric winch line sets that cannot be used for any other purpose. The width of the stored ceiling panels also "kill" the adjacent line sets as well, eliminating up to 12 line sets for theatrical use for non-orchestral programming. The wall towers, although "nestable" in their design, take up valuable off-stage storage space.

Traditional orchestra shell designs have acoustical drawbacks:

• If the shell ceiling design is "open", that is, the openings between the panels are large—then sound is allowed to escape into the absorptive stage loft.
• If the shell ceiling design is "closed", that is, the openings between the panels are minimal—the sound on stage becomes too loud and harsh.
• The volume of the stage platform is small in comparison to the rest of the room which creates two distinctly different acoustical environments.

The "concert hall shaper" solves all the acoustical as well as theatrical difficulties of the traditional design. Here's how it works... The stage house structure, by nature, is inherently solid and hard and rigid—perfect for reflecting all frequencies of sound! Why not use this nature to our benefit and create an acoustical volume on stage that couples or matches that of the house to create more of a one-room hall? And, why not visually match the stage platform architecture to the house architecture so the experience is of being in one room, not the traditional two-room approach of an audience chamber and then a stage inside a proscenium? The "music room first" aesthetic led to these fresh perspectives, and away from the acoustical compromises inherent in traditional multi-use room design.

Continued...