Download Digital Simulation of “Brassiness” and Amplitude-Dependent Propagation Speed in Wind Instruments The speed of sound in air increases with pressure, causing pressure peaks to travel faster than troughs, and leading to a sharpening of the propagating pressure waveform. Here, this nonlinear effect is explored, and its application to brass instrument synthesis and its use as an audio effect are described. Acoustic measurements on tubes and brass instruments are presented showing significant spectral enrichment, sometimes referred to as “brassiness.” The effect may be implemented as an amplitudedependent delay, distributed across a cascade of incremental delays. A bidirectional waveguide, having a pressure-dependent delay, appropriate for musical instrument synthesis, is presented. A computationally efficient lumped-element processor is also presented. Example brass instrument recordings, originally played softly, are spectrally enriched or “brassified” to simulate a fortissimo playing level.
Download Modeling Methods for the Highly Dispersive Slinky Spring: A Novel Musical Toy The ’Slinky’ spring is a popular and beloved toy for many children. Like its smaller relatives, used in spring reverberation units, it can produce interesting sonic behaviors. We explore the behavior of the ’Slinky’ spring via measurement, and discover that its sonic characteristics are notably different to those of smaller springs. We discuss methods of modeling the behavior of a Slinky via the use of finite-difference techniques and digital waveguides. We then apply these models in different structures to build a number of interesting tools for computer-based music production.