Boris Shershenkov - ’Limacon’ demonstration

‘Limacon’ is the musical instrument making audible the topological distribution of vibration modes over the surface of the round idiophones (cymbals) by means of electroacoustic feedback and audio proximity effect. It represents the feedback system where the cymbal acts as a diffuser of a loudspeaker reproducing a mixed signal from eight microphones located under its surface. The French term ‘limaçon’ means ‘snail’ and refers both to the spiral microphone complex hidden under the shell of the cymbal and to the polar pattern of these microphones which on the plane can be shown as a closed curve of a certain shape - cardioid or the limaçon of Pascal.