NEAR FIELD BEAMFORMER DESIGN FOR WIDEBAND LOUDSPEAKER ARRAYS

A loudspeaker array is an arrangement of multiple loudspeakers. Its design finds optimal input weightings of an individual loudspeaker to generate focused sound beam into a target region or angle of interest. The well-posed problem of controlling sound fields with limited boundary values(loudspeakers of the array) can be accomplished by expressing space-averaged potential energy density of a specified region. The brightness/contrast control was proposed by this form, and they have been used for designing near field loudspeaker arrays. In this paper, we setup the problem as an acoustic potential energy density difference between audible and inaudible regions with spatial weightings. Since the defined optimization problem is very sensitive to the spatial weightings, the second optimization problem is defined. Results of the joint optimization show that directional characteristics of the designed beamformer are improved compared with uncontrolled beamformer.