Reduction of the Dispersion Error in the Triangular 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

ABSTRACT

The digital waveguide mesh has been successfully used for simulation of two-dimensional (2-D) and three-dimensional (3-D) wave propagation in musical instruments and acoustic spaces. Nevertheless, digital waveguide mesh algorithms suffer from dispersion which increases with frequency. In this letter, we show how the dispersion error of the triangular digital waveguide mesh can be reduced by frequency warping. By using this technique, the worst-case dispersion error of 0.6% is obtained, whereas in the original triangular mesh it is about 6.5%.

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

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This article was published in IEEE Signal Processing Letters, vol. 6, no. 3, pp. 58-60, March 1999.

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Last modified: February 26, 1999
Author: Vesa Välimäki