Wavefront synthesis using wideband constant delay IIR filters

✍ Scribed by Toyoji Matsumoto; Kiyoshi Nishikawa

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 1002 KB
• Volume: 88
• Category: Article
• ISSN: 1042-0967
• DOI: 10.1002/ecjc.20165

✦ Synopsis

With a view to realizing sound image shifting with a linear speaker array and a two-dimensional digital filter, wavefront synthesis by using low-order low-pass broadband constant delay IIR filters as the one-dimensional filters connected to each speaker is proposed. In the constant delay IIR filter, a bandpass MFD polynomial with a constant delay region wider than the low-pass MFD polynomial in the denominator is used. The amplitude has a flat low range at the set of complex mirror image zeros. As a result of multiple zeros at z = -1 and a set of real image zeros in the neighborhood, a bandwidth equal to the constant delay bandwidth as well as a stopband are formed. For wavefront synthesis, even and odd order constant delay filters and integer delay terms are used to provide the specified delay. The formation of a virtual sound source is confirmed by means of a low-order design example.