Compact acoustic array system using waveguides

Abstract

In the study of acoustic array systems it is usually assumed that the acoustic sources that compose the system are point sources. However, in real life implementations, loudspeakers are used as the acoustic sources of the array. This has three major disadvantages. First, it decreases the performance of the system by introducing directivity patterns different to that of the ideal point source. Second, it limits the inter-element spacing between loudspeakers which results in a limited frequency range where spatial aliasing can be avoided. And third, it increases the overall size and weight of the system making its handling difficult. As the radiation from the aperture of a pipe driven by a loudspeaker approximates that of a point source, the present study aims at developing an array system by using this radiation from open-ended pipes. Considering that the resonances from pipe might deteriorate the performance of the array, the present study begins by proposing the use of the inverse filtering technique to control those resonances. The final stage corresponds to the implementation of an acoustic array which performance is compared from an analytical solution.