Comparison of Pressure-Matching and Mode-Matching Beamforming Methods for Circular Loudspeaker Arrays

摘要

Pressure-matching and mode-matching are two well-known strategies used for the computation of beam-forming digital filters for microphone and loudspeaker arrays. A theoretical comparison is presented of these two methods when these are applied to a circular loudspeaker array mounted on a rigid cylinder. The pressure-matching method is used to generate the desired acoustic pressure at a number of control points arranged in the far field of a circular loudspeaker array, whilst in the case of mode-matching an attempt is made to minimize the squared error between the Fourier coefficients that represent the reproduced and target radiation pattern of the array. It is shown that, in the case under consideration, the two strategies are identical if the effect of spatial aliasing is negligible.