sandbox/soundbox

demonstration

physical design

sandbox/soundbox consists of a rectangular acrylic box filled with a thin layer of natural sand from the shore of Lake Michigan. There is ample free space within the box to enable the sand to flow freely when the box is moved and tilted. The sides of the box are connected with small screws that fasten into ‘connector cubes’ at the corners, but in its prototype version, several of the box’s seams had to be reinforced with electrical tape.

sensors

sandbox/soundbox utilizes a Piezo contact microphone and a GY-521 MPU6050 3-axis accelerometer. The Piezo is secured in roughly the center of the bottom panel of the box. It is soldered to an XLR cable that is able to plug directly into an audio interface. The accelerometer is mounted on the side of the box, near a corner in order to obtain the most dramatic readings. It is connected via jumper wires to an Arduino Uno. The Arduino connects to a computer via USB cable, the Piezo connects to an audio interface via XLR cable, and the interface connects to the computer via USB cable.

programming

The sound from the Piezo contact microphone is routed through an audio interface and then into Max. The readings from the accelerometer are then used to control various parameters of sound that are applied to the sound coming in from the Piezo. The accelerometer takes six readings total. Of those six, four of them are mapped onto parameters of a “yafr2,” or reverb, Max patch: size (room size), decay time, damping, and diffusion. The remaining two accelerometer readings are mapped onto parameters of a “degrade~” Max object: sampling-rate ratio and resolution in bits. These parameters affect the sound based on the orientation of the accelerometer, but the original Piezo-captured sound always comes through as well, to maintain the connection to the original sound source.