Efficient simulation of acoustic physical models with nonlinear dissipation

One long-term goal of physics-based sound synthesis and audio effect modeling has been to open the door to models without a counterpart in the real world. Less explored has been the fine-grained adjustment of the constituent physical laws that underpin such models. In this paper, the introduction of a nonlinear damping law into a plate reverberation model is explored, through the use of four different functions, transferred from the setting of virtual-analog electronics. First, a case study of an oscillator with nonlinear damping is investigated. Results are compared against linear dissipation, illustrating differing spectral characteristics. To solve the systems, a recently proposed numerical solver is employed, that entirely avoids the use of iterative routines such as Newton-Raphson for solving nonlinearities, thus allowing very efficient numerical solution. This scheme is then used to simulate a plate reverbation unit, and tests are run, to investigate spectral variations induced by nonlinear damping. Finally, a musical case is presented that includes frequency-dependent damping coefficients.