Effects ( DAFx -02), Hamburg, Germany , September 26 2002, pp. 13-20, https://ccrma.stanford.edu/ jos/doppler/ . 122 S. Serafin, C. Wilkerson, and J. O. Smith, ``Modeling bowl resonators using circular waveguide networks'', in Proceedings of the COST-G6 Conference on Digital Audio Effects ( DAFx -02), Hamburg, Germany , September 26 2002, pp. 117-121, http: //www. dafx