Generative Feedback Networks Using Time-Varying Allpass Filters
Greg Surges, Tamara Smyth, Miller Puckette · University of Michigan Library Repository · 2015
This work builds upon existing work in which second-order allpass filters are used in a feedback network, with parameters made time-varying to enable effects such as phase distortion in a generative audio system; the term “audio” is used here to distinguish from generative “music” systems, emphasizing the strong coupling between processes governing the production of high-level music and lower-level audio. The previous system was subject to issues of instability that can arise when time-invariant filter parameters are allowed to vary over time. These instabilities are examined herein, along with the adoption of a power-preserving rotation matrix formulation of the allpass filter to ensure stability and ultimately an improved synthesis for a generative audio system.