Augmented active acoustics: Recent experiences in acoustical enhancement for modern musical performance

Abstract

Electronic acoustic enhancement systems allow the designer to implement traits not easily obtained with physical construction, or to provide variable room behavior to accommodate different program needs in a multi-purpose facility. Traditionally, most active acoustic systems have been employed for the enhancement of acoustic music, speech, and other classical program material. Here, we provide an overview of active enhancement methods particularly suited to contemporary, amplified musical performances. By accurately modeling and simulating the geometry of the performance space, naturally occurring reflection paths may be augmented with their synthetic counterparts, each rendered with high spatial fidelity but modified acoustic properties. Material characteristics may then be selected beyond what is practical in the built environment, and room signatures may be modified and changed over time. Real-time signal processing placed in-line with an audio mixing console then renders these sound fields into a collection of loudspeakers throughout the listening space. Examples are provided of auditoria where these systems have been installed, along with measured acoustical behavior demonstrating both the effectiveness of the technique and practical design constraints for implementation.