Introduction

The sound that we hear in a critical listening room is determined by the complex interaction among the quality of the electronics, the quality and the placement of the loudspeakers, the hearing ability and placement of the listener, the room dimensions (or geometry if non-cuboid), and the acoustical condition of the room's boundary surfaces and contents. All too often these factors are ignored and emphasis is placed solely on the quality of the loudspeakers. However, the tonal balance and timbre of a given loudspeaker can vary significantly, depending on the placement of the listener and loudspeaker and the room acoustic conditions. The acoustic distortion introduced by the room can be so influential that it dominates the overall sonic impression.1 ^,2 The two causes of this acoustic distortion are the acoustical coupling between the loudspeakers and listener with the room's modal pressure variations or room modes and the coherent interaction between the direct sound and the early reflections from the room's boundaries.

Critical listeners have invested considerable time in trial-and-error attempts to minimize these effects. However, no automated method to search for the optimum locations has been proposed. With the advent of 5.1 home theater and multichannel music, physical trial-and-error approaches become even less feasible. The task of optimally locating five loudspeakers and multiple subwoofers presents a significant challenge. In addition to optimizing the low-frequency response via optimum listener and loudspeaker placement, one must also address imaging3 ^,4 and the influence of acoustical surface treatment on the size...