Arcuate loudspeaker array for enhanced diffuse acoustic field synthesis: A comparative study with linear arrays

Abstract

Diffuse acoustic fields are widely employed for material testing in industry, and loudspeaker‐array synthesis offers high accuracy and flexible control. However, prior work has focused primarily on linear or planar arrays, with little attention to curved geometries. In this study, we introduce an arcuate loudspeaker array for diffuse acoustic field synthesis and compare its performance to that of a one‐dimensional linear array across three metrics: synthesis accuracy, transfer‐matrix condition number, and energy concentration within a prescribed sector. Loudspeaker directivity is modeled as frequency‐dependent: at low frequencies each unit behaves as an ideal monopole (omnidirectional), while at mid frequencies an acoustic‐center‐compensated source model captures weak directivity. To explain the observed differences, we analyze wavefront matching via Huygens’ principle and spectral concentration through spatial wavenumber decomposition. Numerical simulations demonstrate that the arcuate array outperforms the linear array in mid‐to‐high frequency bands, achieving both lower synthesis error and higher sector energy concentration. These findings are validated experimentally in an anechoic chamber using eight‐unit linear and arcuate arrays. Our results show that a curved array geometry more effectively focuses diffuse energy into the target region, reducing leakage and enabling high‐precision field synthesis.