Product directivity models for parametric loudspeakers.
Date of Issue2012
School of Electrical and Electronic Engineering
In a recent work, the beamsteering characteristics of parametric loudspeakers were validated in an experiment. It was shown that based on the product directivity model, the locations and amplitudes of the mainlobe and grating lobes could be predicted within acceptable errors. However, the measured amplitudes of sidelobes have not been able to match the theoretical results accurately. In this paper, the original theories behind the product directivity model are revisited, and three modified product directivity models are proposed: (i) the advanced product directivity model, (ii) the exponential product directivity model, and (iii) the combined product directivity model. The proposed product directivity models take the radii of equivalent Gaussian sources into account and obtain better predictions of sidelobes for the difference frequency waves. From the comparison between measurement results and numerical solutions, all the proposed models outperform the original product directivity model in terms of selected sidelobe predictions by about 10 dB.
DRNTU::Engineering::Electrical and electronic engineering
Journal of the acoustical society of America.
© 2012 Acoustical Society of America. This paper was published in Journal of the Acoustical Society of America and is made available as an electronic reprint (preprint) with permission of Acoustical Society of America. The paper can be found at the following official DOI: [http://dx.doi.org/10.1121/1.3682035]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.