Analysis and Synthesis of Coupled Vibrating Strings Using a Hybrid Modal-Waveguide Synthesis Model

The linear coupling of two strings or of a single string vibrating in two orthogonal polarizations leads to two observable phenomena: two-stage decay and beating. In this paper, we present methods for accurately measuring and modeling the lower partials of a recorded guitar tone, where coupling effects are most audible. These estimated parameters are then used for accurate resynthesis in a hybrid modal/waveguide model. We make use of the fact that two-stage decay occurs in analyzed tones to allow direct measurement of sinusoidal decay rates. A traditional iterative optimization algorithm is explored and found to be most effective in the special case when only beating occurs. Sound examples are provided on the Web.