Extending Digital Waveguides To Include Material Modelling
Digital Waveguides have been extensively used for musical instrument and room acoustics modelling. They can be used to form simplistic models for ideal wave propagation in one, two and three dimensions. Models in 1D for string and wind instrument synthesis and more recently a model for a drum, realised by interfacing 2D and 3D waveguide meshes, have been presented [1]. A framework is thus in place for the virtual construction of new or abstract musical instruments. However, straight-forward waveguides and waveguide meshes behave in an extremely indeal nature and phenomena such as stiffness and internal friction are often compromised or ignored altogether. In this paper we discuss and evaluate models which incorporate material parameters. We review a 1D bar model, and then present a 2D extension to model plates. We also discuss the problem of modelling frequency dependent damping, by describing a waveguide model of a visco-elastically damped string.