The Symbaline - An Active Wine Glass Instrument with a Liquid Sloshing Vibrato Mechanism

Abstract

The Symbaline is an active instrument comprised of several partly-filled wine glasses excited by electromagnetic coils. This work describes an electromechanical system for incorporating frequency and amplitude modulation into the Symbaline’s sound. A pendulum having a magnetic bob is suspended inside the liquid in the wine glass. The pendulum is put into oscillation by driving infra-sound signals through the coil. The pendulum’s movement causes the liquid in the glass to slosh back and forth. Simultaneously, wine glass sounds are produced by driving audio-range signals through the coil, inducing vibrations in a small magnet attached to the glass’s surface and exciting glass vibrations. As the glass vibrates, the sloshing liquid periodically changes the glass’s resonance frequencies and dampens the glass, thus modulating both wine glass pitch and sound intensity.