Acoustics of Clowes Memorial Hall, Butler University, Indianapolis, Indiana

Abstract

This 2100-seat auditorium, inaugurated 18 October 1963, on the campus of Butler University, serves as the home of the Indianapolis Symphony Orchestra and as a convocation hall for the University. This auditorium, designed by John M. Johansen and Evans Woollen, III, has three shallow balconies that extend down the side walls of the hall to within 30 ft of the proscenium opening. The roof-deck serves as the upper limit of the acoustical chamber, and several feet below the roof-deck is suspended an array of plywood sound-reflecting panels. The side walls are plane surfaces (minimum dimension, approximately 15 ft) parallel to the main axis of the hall. The side-balcony spandrels are also plane surfaces, of exposed concrete, parallel to the main axis. Much of the wall surface consists of plaster applied directly to concrete masonry units, and the remainder is plywood panelling secured to furring strips. All rear-wall surfaces are hard plaster, parallel to the proscenium wall. The aisle areas of this auditorium are extensive, and to secure sufficient reverberation for music no carpet was installed in the aisles of the three balcony tiers. The design for this hall was essentially complete by late fall 1959. This paper presents results of acoustical measurements in the hall and direct evaluations made during actual events in the hall during the past few months.