installation for computer, 4 loudspeakers, microphone and beamer
by Max Jacob

 

Risonanze lets resonate the ambiance sound through sixteen virtual resonators whose pitches are determined over time by an evolutive process adapting to the phonic characteristics of the venue. The intensity of each resonator drives a colored sphere, projected from the ceiling on the floor or on a wall. The sounds and images reflect densities, rarefactions, internal structures and relationships of the sound captured in the venue.

The installation is thought for a quite dark ambiance, of about 4x4x4m, but can be adapted to different situations. The space is crossed by sounds which move around, transform, die and are newly born infinitely. In correspondence to every sound, a beam of colored light is projected on the floor or, where this is not possible or not adequate, on a wall or directly by a large display. The light beams turn around, grow and shrink, change colour, die and are born again, reflecting the evolutions of the sound.

Sounds and images are generated in real time by a computer which processes the signal captured by a microphone put the middle of the installation.

The computer simulates the behavior of 16 resonators (objects which resonate at a given pitch), tuned on different frequencies. Every resonator resonates in sympathy with the captured sound, becoming more or less intense depending on how much its frequency is present. Every resonator operates inside a band of a third of octave, covering complexively from 65 to 2500 Hz.

At the same time, the computer analyzes as well other 16 frequencies, one for each band. If this secondary frequency has a better match with the ambiance (what means that it would resonate more than the one on which the current resonator is tuned on), the current resonator is replaced by one tuned on the new frequency. This mechanism leads to the selection of the frequencies which are the most resonating ones inside the installation venue, being thus able to catch the evolutions in density, dynamic and spectrum which create the multimedia score in real time. The 16 resonators as a whole will tend to reflect hidden harmonic relations operating in the captured venue.

Every resonator drives a colored sphere, which gravitates around the center of the room (or of a wall) on a circle whose radius is proportional to the pitch of the resonator. The size of the sphere follows the intensity of the resonance, while its position determines the position of the resonating sound in the quadriphonic space. Every new born resonator generates a pink sphere, whose colour slowly changes through the whole spectrum (purple, blue, green, yellow and, finally, red). The colours of the spheres reflect the ages of the correspending resonators. Older resonators are those for which the computer wasn't able for a long time to find a better matching frequency inside the same band. Only few resonators will live long enough to become red, most will die before. And since the ambiance is likely to change over time, the old ones will sooner or later be replaced as well.

The heart of the installation is a software in Pure Data + Gem, running on Linux (only free software is employed). The software processes a monophonic input stream coming from the microphone and generates a quadriphonic output stream and the video. Computer and software are delivered by the author. Other necessary equipments are a microphone and, depending on the venue, a beamer, large display or display matrix.

A video capture (11.3 MB) of a couple of minutes of the software fed by the sound of a city road at day. The resolution is quite low and compression quite high. The quadriphonic audio stream has been projected on the X axis in order to produce a stereophonic sound.

A sound example (3.6 MB) captures the audio output of the software fed by the ambiance sound taken inside a public library.

Screenshots

Curriculum vitae of Max Jacob in pdf