Rensselaer Polytechnic Institute

SenSInstallation:

Review the use of spherical speaker arrays and sensor-speaker arrays (SenSAs) in performance and installation.

Detail our recent development of “third generation” spherical speaker arrays.

Project the use of these new speakers as a large-scale diffusion array for sound installation and electro-acoustic performance.

“Alternative Voices for Electronic Sound”Trueman, Bahn, Cook - ICMC 2000, Berlin

“Physicality and Feedback”Bahn, Hahn, Trueman - ICMC 2001, Havana

SenSInstallation Project Goals:

Construct a new Sensor/Speaker “instrument:”

• Large-scale multi-channel spherical sound system under sensor control.

• Develop the system so that could support many configurations and applications.

• Develop general-purpose spatialization tools for the system.

• Realize numerous pieces ranging from sound installation to electro-acoustic mixed ensemble compositions.

Conventional Systems:• Covered at SEAMUS 2002 by Beck: A Taxonomy of Sound

Diffusion

• Forward projecting stereo “PA-systems”

• Outside-In, “Surround” configurations

Spherical Speaker Arrays and “SenSAs:” Background

Conventional Systems:• Surround the audience in order to provide an “immersive”

sonic experience.

• Disassociate the acoustic source of sound production and the electronic image creating a “plane of separation” between acoustic and electronic sources and between electronic sounds and the audience.

• Acoustic sources are absorbed into electronic sound-space, usually via subtle addition of artificial reverberation (sound reinforcement)

Spherical Speaker Arrays and “SenSAs:” Background

Spherical Systems:

• “Inside-Out,” instrument-like sonic radiation

• Engage natural acoustic qualities of performance spaces

• No “sweet spot”

Spherical Speaker Arrays and “SenSAs:” Background

Spherical Systems:• Electronic sources are absorbed into the acoustic sound-

space

• Very successful with small chamber music ensembles and in small spaces.

• Often successful with larger ensembles, in large spaces, and in combination with traditional sound-reinforcement systems.

• No “plane-of-separation” between electronic and acoustic sources.

Spherical Speaker Arrays and “SenSAs:” Background

Spherical speakers have long been applied in the study of

• The acoustic qualities of performance spaces:

Hidaka and Beranek, 1991

• The acoustic qualities of instruments:

Causse, et al., 1992

Roads, 1996

Wessel, 1991

Spherical Speaker Arrays and “SenSAs:” Background

L.A.R.S. speaker used inacoustic analysis of concert halls

Multi-channel microphone array

Software interface to manipulate and apply impulse response analyses

The “Nbody Project” Cook and TruemanStudies of the directional radiative qualities of acoustic instruments

Early Spherical Speakers for the Nbody Project

The Bomb

The Boulder

Trueman’s first “gigging” sphere “R2”

(Ikea salad bowls never sounded better…)

the “critter”12 discreet channels

individually enclosed drivers

Designed by Dan and Lawrence Trueman

“Bubba” (Bahn)A 23” 12-channel spherical speaker array

based on the “critter” design

Second Generation Spherical Speakers

U.S. Enclosures Inc. Fabricated Spheres

Applications:

Performance Arrays

• Bahn

• Trueman

• “Interface”

Bahn set-up

“The r!g”

Trueman set-ups

solo

Trueman set-ups

Electro-Acoustic mixed ensembles: Trollstilt, Machine Language

“Trollstilt”Dan Trueman &Monica MuganColgate Chapel

“interface” on stage at OSU Interactive Performance Series

Applications:Sensor Speaker Arrays: SenSAs

• Trueman: BoSSA• Cook: DigitalDoo• Bahn/Hahn: Pikapika

BoSSA Bowed-Sensor-Speaker-Array

Cook’s DigitalDoo: a sensor didgeridoo

Cook’s DigitalDoo: modified spherical speaker

““Pikapika”Pikapika” a Sensor/ Speaker Performer - Tomie Hahn and Curtis Bahn

The “SSpeaPer” Interface

“Strolling:” a wireless sonic performer

Applications:Multi-channel Arrays and

SenSAs in Installation

• Cook: Perisphere 1• Moore, Engel, Place: Telephonic Displacements• Moore: Cumulosonus

PariSphere 1Cook

Multi-channel speaker array forTelephonic Displacements

Moore, Engel, Place

Cumulosonus 12 channel/ 48 speaker array - Moore

Third Generation Spherical Speakers

• Due to dissatisfaction with United Enclosures Inc. fabricated spheres, new speakers returned to a modified “critter” design.

• Designed for 2 channel spherical or 1 channel hemispherical applications

• 43 single channel hemispheres produced

Third Generation Spherical Speakers

Design and fabrication

Jigs created for accuratemass production

Third Generation Spherical Speakers

Sealing the hemispheres

Preparation for painting

Third Generation Spherical Speakers

Third Generation Spherical Speakers

Third Generation Spherical Speakers

Third Generation Spherical Speakers

Installing Polk Audio coaxial drivers.

Initial Tests

First configuration:16 channel 4x4 test grid

Initial Tests

Currently undergoing rigorous evaluation process…

Initial Tests

Surveillance dome for soft VNS head tracking

• 4x4 matrix panning based on “equal power curve” function, later Gaussian or “S-curve.”

• Arbitrary room size and speaker configuration.

• Dynamic placement of sound “objects” within the configuration.

• Scalable sound size or “radius.”

• Hooks for external control of sound object placement.

Initial Software Tests

Initial Software Tests

Based on Simon Fraser's implementation of Craig Reynolds' Boids algorithm

“Boids,” Eric L. Singer

Pieces in Progress

• “TerraSonus” Moore Installation of a large-scale navigable sonic landscape

• “struct_1.cg.0” Trueman/Bahn A “Digital Concerto Grosso” for Electronic Duo and Large Chamber Orchestra

Building new sonic display systems is a very rewardingactivity:

Speakers constitute our “voice” in electronic music yet we rarely engage them on this level when studying electro-acoustic music composition and performance.

This project provides engagement with design, fabrication, acoustics, electronics, programming, and composition. Great class or independent project for students.

No, we’re not selling them...

We will provide you with plans and information if you want to build some.

Curtis Bahn crb@rpi.eduhttp://www.arts.rpi.edu/crb

Stephan Moore stephan@oddnoise.comhttp://www.oddnoise.com/

Thanks to the Integrated Electronic Arts ProgramRensselaer Polytechnic institute - iEAR Studios.Polk Audio, Inc.

Partners in crime:

David Lublin, Jonathan Marcus - Undergraduate Research Assistants

Scott Smallwood, Dan Trueman, Perry Cook

Interface at the Flea Theater in NYC April 15th, EMF seriesBahn, Trueman, Cook, Hahn, Dubois