A Directional Loudspeaker Array for Surround Sound in Reverberant Rooms
Terence Betlehem, Craig A. Anderson · 2010
We present a method to enhance the performance of the sound field reproduction approach to 2-D surround sound applicable for reverberant rooms, under the constraint that only a small number of loudspeakers is permissible. The method is based on the idea of using steerable directional loudspeakers to exploit the room reverberation. In home theater applications, exact sound field reproduction is currently handicapped by the unreasonably large numbers of loudspeakers required for operation over audible frequencies. However by exploiting reverberant wall reflections, mirror-sources may be used as additional loudspeakers to help perform the reproduction. Utilizing mirror-sources, the number of loudspeaker locations required throughout the room may be reduced. A large array of omnidirectional loudspeakers can then be replaced by a small number of compact configurable directional loudspeakers. Simulating in a reverberant room with each directional loudspeaker modeled as an array of monopoles, we show that the performance is comparable to a circular array with a much larger number of elements. We quantify the accuracy of the sound field reproduction and the robustness to calibration error, comparing the proposed scheme with the more standard circular array geometry.