First-Order Loudspeaker Design and an Experimental Application on Sound Field Reproduction With Sparse Equivalent Source Method

In this paper, a first-order loudspeaker, which is composed of monopole and dipole units, is designed and manufactured. The structure and size of the loudspeaker is shown. It is able to control the sound energy radiation with first-order beam control. The directivity of the loudspeaker is measured with a turntable and microphone arm. The directivity control ability is examined by the synthesis of a cardioid directivity. After that, a circular first-order loudspeaker array is constructed in order to investigate the array’s performance on sound field reproduction system with exterior cancellation. The reproduction and energy radiation control performance of this first-order loudspeaker array is compared with a monopole array by experiment in the free field. At last, in order to reduce the effort on the loudspeaker array acoustic transfer function measurement, a sparse equivalent source method is proposed. The performance of the proposed method is compared with the conventional pressure-matching method and a previous equivalent source method.