MAS.960 Final Project

Motivation

The motivation behind this project was the need for a granular synthesis controller that would benefit both the granular synthesis community and the music controller community. I wanted to create an innovative controller that allowed me to produce, manipulate and experience the sounds generated by this method of synthesis. A foam ball was chosen as the interface because it has an intriguing texture and malleability, which lends itself well as an expressive electronic music controller.

Hardware & Electronics

‣Foam Ball
‣Arduino Board
‣Sensors
‣Analog Devices ADXL203 +/-1.5g 2-Axis Accelerometer
‣Sparkfun Accelerometer Breakout Board - ADXL203CE +/-1.5g
‣4 Force Sensing Resistors (0.5” Circle)

The X and Y analog outputs (XA & YA) of the ADXL breakout board are sent directly to two of the analog inputs on the Arduino board. The accelerometer sits on top of the cardboard sensor box, roughly in the absolute center of the squishy blue ball.

The conditioning circuit for the FSR's consists of a simple voltage divider, where Rf is the FSR and Rm is a 10K resistor. The output of each voltage divider circuit is then sent to four remaining analog inputs of the Arduino board. The four FSR's are placed on each side of the sensor box.

Could I Interest You in a Squishy Blue Ball?

Squishy Blue Ball

Arduino Board

ADXL Breakout Board

Accelerometer Board

Force Sensing Resistor

Voltage Divider

Sensor Box - View 1

Sensor Box - View 2

Sensor Box Cavity

Sensor Box Installed

Arduino + Sensor Conditioning Circuit

Complete System

Granular Synthesis

Granular synthesis is a sound synthesis method that operates on the microsound time scale. It is often based on the same principles as sampling but often includes analog technology. The samples are not used directly however, they are split in small pieces of around 1 to 50 ms (milliseconds) in length, or the synthesized sounds are very short. These small pieces are called grains. Multiple grains may be layered on top of each other all playing at different speed, phase and volume.

The result is no single tone, but a soundscape, often a cloud, that is subject to manipulation in a way unlike any natural sound and also unlike the sounds produced by most other synthesis techniques. By varying the waveform, envelope, duration, spatial position, and density of the grains many different sounds can be produced.

The result is usable as music, sound effects or as raw material for further processing by other synthesis or DSP effects. The range of effects that can be produced include amplitude modulation, time stretching, stereo or multichannel scattering, random reordering, disintegration and morphing.

Dennis Gabor researched how human beings communicate and hear. The result of his investigations was the theory of granular synthesis, although Greek composer Iannis Xenakis claimed that he was actually the first inventor of this synthesis technique (Xenakis, Formalized Mmposer Barry Truax was one of first to implement real-time versions of this synthesis technique.

-- From Wikipedia, the free encyclopedia

Software and Mapping

‣Max/MSP as granular synthesis engine and mapping environment
‣Simple Message System to transfer analog sensor signals from Arduino to Max/MSP
‣Granular Toolkit for Max/MSP to synthesize audio