Variable acoustics for multi‐use halls using electronic reflected energy systems

Abstract

The classic problems of the multi‐use hall physically designed to meet symphonic performance criteria, are the extended times and high sound pressure levels of the reflective field. Bolt Beranek & Newman, Inc. and George Izenour pioneered the concepts of variable physical acoustic characteristics in hall design, by moving room ceilings to reduce volume and introducing variable absorption in the form of tracked drapery and banners. The philosophy of this approach, is to design the room for natural symphonic conditions, and vary the acoustics for opera and amplified musical theater and popular programs. Concurrently, Parkin, Veneklasen, and others were working on the premise of designing a room with short reverberation times for opera and amplified programs and extended the reflections required for symphonic performance electronically. In 1971 Jaffe, on the basis of the psycho‐acoustic research of Beranek and Schultz began to develop electronic systems simulating specific bits of reflective energy critical to the perceptions of presence, definition, and warmth. This paper describes the systems developed, measured results, and the response of the musical community to the use of electronics to provide reflective energy.