In recent months, composer Giuseppe Tamborrino has been using Kyma for a sonic exploration of feedback on recycled percussion instruments. When he started connecting these instruments to each other, he discovered a complex physical system that significantly increased their timbral capabilities.
Following the research of Agostino Di Scipio and his “acus-mate” concept — in which speakers become instruments — Tamborrino employed four Bluetooth 5.0 speakers as both instruments and drumsticks. This allowed him to send low-frequency sounds through a portable quadraphonic system in Kyma.
Technically, his system uses pulse synthesis and several prototypes of buffers (MIDI-mapped with an Apple Watch), along with morphing and real-time hierarchical control of eight microphones. These microphones are strategically placed on amplified resonators and spring-friction systems. This setup is occasionally used to move sound across membranes and within reiteration spaces.
A key factor in the emergent complexity is the latency inherent in the Bluetooth 5.0 stereo transmitters and receivers. This latency delays the sounds and stabilizes them into new, transformed sound textures. These sounds are then refracted by the resonances and spectral coloring emitted by the percussion instruments.
The feedback oscillation sometimes generates rhythms through the movement of springs and the percussion on the microphones. This creates a symmetrical electro-acoustic interplay where waves propagate, changing direction, and decay on varying time and spatial scales.
Tamborrino also uses this system to explore “underwater loop-back” by placing a mobile phone and a Bluetooth speaker inside a tube to visualize wave propagation.
This research was made possible with thanks to Laura Tedeschini of the University of Roma Tre.