Reduction of the Dispersion Error in the Interpolated Digital Waveguide Mesh Using Frequency Warping

Lauri Savioja and Vesa Välimäki

Helsinki University of Technology, Laboratory of Acoustics and Audio Signal Processing, P.O. Box 3000, FIN-02015 HUT, Espoo, Finland


The digital waveguide mesh is an extension of the one-dimensional digital waveguide technique. The mesh is used for simulation of two- and three-dimensional wave propagation in musical instruments and acoustic spaces. The rectangular digital waveguide mesh algorithm suffers from direction-dependent dispersion. By using the interpolated mesh, nearly uniform wave propagation characteristics are obtained in all directions. In this paper we show how the dispersion error of the interpolated mesh can be reduced by frequency warping. By using this technique the bandwidth where the frequency accuracy is within 1% tolerance is more than doubled.

Keywords: acoustic delay lines, acoustic signal processing, multidimensional system, time-domain finite-difference method

This paper was published in the Proceedings of the 1999 International Conference on Acoustics, Speech, and Signal Processing (ICASSP'99), vol. 2, pp. 973-976, Phoenix, Arizona, March 15-19, 1999.

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Last modified: 14 April, 1999
Author: Vesa Välimäki