Acoustics of La Grande Salle, Place des Arts, Montréal, P. Q., Canada

Abstract

This multipurpose auditorium, designed by Affleck, Desbarats, Dimakopoulos, Lebensold, and Sise, was inaugurated 21 September 1963. About one-third of its 2980 seats are located on the main floor, with the balance distributed in three balconies and three tiers of boxes along the side walls. It is equipped with a mechanized concert enclosure of wood secured to a steel frame, as this hall was built to provide a home for the Montréal Symphony Orchestra, ballet, opera, and revues. The front third of the audience chamber is approximately 80 ft wide, but the balconies at the rear of the house were designed with much more width to accommodate the number of seats specified by the building owner. Most of the wall surfaces, including the rear walls, were constructed of plaster applied directly to concrete masonry units or poured concrete to obtain sufficient low-frequency reverberation. The small areas of wood paneling are securely cemented to heavy masonry walls for the same reason. To obtain sufficient reverberation for music, the upper boundary of the audience chamber was constructed approximately 80 ft above the main floor. Small sound-reflecting surfaces were installed below the “upper ceiling” to aid definition. These small surfaces were designed in the form of an interwoven grid, which conceals the air-supply ducts, the loudspeaker equipment, and theatrical and audience lighting equipment. The basic design of the auditorium was accomplished between September 1958 and January 1959. This paper reports the results of acoustical measurements performed in the hall since its completion and observations made during a wide range of speech and music performances.