aTechnion - Israel Institute of Technology
bTel Aviv University
Abstract :
The Symbaline is an active instrument consisting of water tuned
wine glasses excited by electromagnets. Its timbre is
characterized by steady overtones and a smooth attack-decay
envelope. In this presentation we describe an
electromechanical system for adding vibrato to the Symbaline’s
sound. The system consists of a pendulum with a magnetic bob,
submerged inside the liquid in the wine glass. Infra-sound signals
are sent to an electromagnet external to the glass, generating a
magnetic field which puts the pendulum into oscillation. As a
result of the pendulum’s movement the liquid in the glass sloshes
and the water level fluctuates in a periodic manner. Audio
frequency signals are sent to the same electromagnet, in
parallel, inducing vibrations in the wine glass itself, by exciting a
small magnet on the glass’s surface. While the glass is radiating
sound, its resonance frequencies are altered by the changing
water levels, resulting in frequency and intensity modulation.