Towards A Virtual-Acoustic String Instrument
Sandor Mehes, Maarten van Walstijn and Paul Stapleton
This paper was originally presented at SMC16 Hamburg, Germany
Abstract
In acoustic instruments, the controller and the sound producing system often are one and the same object. If virtual-acoustic instruments are to be designed to not only simulate the vibrational behaviour of a real-world counterpart but also to inherit much of its interface dynamics, it would make sense that the physical form of the controller is similar to that of the emulated instrument. The specific physical model configuration discussed here reconnects a (silent) string controller with a modal synthesis string resonator across the real and virtual domains by direct routing of excitation signals and model parameters. The excitation signals are estimated in their original force-like form via careful calibration of the sensor, making use of adaptive filtering techniques to design an appropriate inverse filter. In addition, the excitation position is estimated from sensors mounted under the legs of the bridges on either end of the prototype string controller. The proposed methodology is explained and exemplified with preliminary results obtained with a number of off-line experiments.
Video
The videos below give an impression of how the newest version of the instrument works across a range of the physical parameter settings.
Investigative Sound Examples
Below a range of sound examples exemplifying the role of the estimation of the excitation force.
Experimental Sound Examples
A few sound examples with extreme parameter setup to demonstrate the capabilities of physical modelling.