THE SCIENCE AND APPLICATIONS OF ACOUSTICS - H. H. Arnold ...

262 11. Acoustics of Enclosed Spaces: Architectural AcousticsFigure 11.8. Three basic hall configurations: rectangular, fan shaped, and horseshoeshaped.(1887) in Amsterdam, the Sidney Opera House (opened in 1973), and the ColoradoSymphony’s Boettcher Concert Hall in Denver (opened in 1978 and acousticallyremodeled in 1993) are examples of this type of facility.The rectangular hall is quite traditional, and it has been built to accommodateboth small and large audiences. But these halls will always generate cross reflections(flutter echoes) between parallel walls. Sound can also be reflected fromthe rear walls back to the stage, depending on balcony layout and the degree ofsound absorption. These reflections can help in the buildup of sound and providesa reasonable degree of diffusion in halls of modest interior dimensions. A considerablylarger hall can result in standing wave resonances and excessive flutterechoes.It is interesting to note that the first music hall to be designed from a scientificviewpoint, by none other than Wallace C. Sabine, is the Boston Symphony Hall(1900), views of which are given in Figures 11.9 and 11.10. The structure containsa high, textured ceiling and two balconies extending along three walls. Volume is602,000 ft 3 ; seating capacity 2631; and the reverberation time in the 500–1000 Hz