Doppler Machine

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  Large doppler machine (section)

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  Small doppler machine

Inspired by pieces such as Luigi Russolo’s “Intonarumori”, Steve Reisch’s “Pendulum Music” and Ray Lee’s “Chorus”, as well as the Leslie Speaker, I wanted to work particularly with the Doppler Effect, and how it can be used as a compositional tool, as well as creating a greater understanding of the effect itself to a broader public. I’ve been particularly interested in the usage of feedback along with the Doppler Effect, and creating a more performative piece using microphones to interact with the disc, and thus creating quite ephemeral, alien-esque soundscapes.

It consists of a rotating disc with speakers, which receive the input from a microphone, creating interesting feedback patterns depending on where you position the microphone, and at what speed you run the disc.

The disc is run using a DC motor, running on 9v, with a slip ring to give power to the speakers while it's in rotation. I built a small side panel with a couple of potentiometers for controlling volume and gain, the motor speed and to plug in the microphone. The motor speed is controlled through a constant PWM signal from an Arduino (with a transistor to control the high current). The audio circuit is a really low-fi one, built using an LM386N chip.

Part of my MA final project work at the Royal College of Art, it developed into a larger piece which I've done shows and performances with at various UK venues, and also a few with the very lovely Hackoustic team.

Built With

• arduino
• basic-electronics
• lasercut-acrylic
• low-fi-audio-circuit
• speakers