Numerical Directivity Simulations Of Speaker Arrays For Omnidirectional Sound Source Quality Assessment

Omnidirectional sound sources are standard devices used in numerous acoustic measurements, such as the ones described in ISO3382, ISO140, or ISO354 standards. They are used when information on the sound diffraction at an object is required. State of the art findings describe several engineering designs of omnidirectional sound sources; some commercial applications can be also found. However, there is no universal design method for this kind of sound sources, neither in terms of the size and number of the transducers nor any general electroacoustic principles. This paper describes the use of Finite Elements Method (FEM) to derive the directivity patterns of different speaker arrays, such as spherical speaker arrays and the most popular polyhedrons. The number of transducers studied in the paper varies from 4 to 36. The influence of transducer size and the enclosure size was also preliminarily investigated. The simulation results were assessed with new strict omnidirectionality quality measures, and the influence of the transducers' number or size on a final omnidirectional sound source performance was verified.