Room acoustics and sound system design

At the present time, there are in operation a large number of sound amplification systems installed mainly for the purpose of speech reinforcement. Many of the existing systems appear to have been installed without regard for the acoustical requirements for high speech intelligibility, and the phrase "public-address system" has become almost an anathema to sensitive listeners. Bolt Beranek and Newman, Inc. has become involved in the design of sound amplification systems in conjunction with other aspects of architectural acoustics. A number of principles have been developed as guides for the design of speech reinforcement amplification systems that provide a high degree of intelligibility and naturalness. These principles will be discussed and illustrated by the designs of several typical speech reinforcement systems, including those installed in a large exhibition hall, a reverberant church, a stockholders' meeting room, and an auditorium designed for maximum "natural" reinforcement by proper acoustical design.