Details - communication between the two concert halls

In order to communicate correctly during the preparation, the rehearsal and the performance of ius lucis, it is important to create adequate ways of visual and audio communications between the two places.

Audio intercom

In addition to a conventional audio intercom between the technical teams, we used a dedicated telephonic line between the sound regies.

network messaging

The computers are connected via an internet line. The computer music designers responsible of the transformations were communicating informations during the rehearsal via the iChat messaging software.

Video projection

For the musical synchronisation of the ensembles, the 6 musicians in room B should have a video image of the conductor located in room A. As they are separated from each other, each one of these musicians have a video monitor.

Details - Midi Devices

Midi Keyboard in ensemble A

All the electronic events of ius lucis are triggered by the Midi keyboard playing in ensemble A. It should have 88 keys and the possibility to send program changes. This keyboard is directly connected to the computer of room A. These informations are sent to the room B computer thru UDP vi the ethernet line (see patch UdpToEspro in main max patch).

Midi Mixers

To control the live balance of the transformation, two midi mixers (one in each room) are used. 8 faders controls the levels of the different "voices" of cross synthesis (see score)

Ius lucis control panel subpatch

Details - Computers audio inputs

Ensemble A

There is 2 microphone for the Bb clarinet : one in front of it. and another one off axis by approx. 1 meter. This microphone is used for movement detection of the clarinettist in several sections of the work

The 3 trios are premixed.

Ensemble B

There is 2 microphone for the Bb clarinet : on in front of it. an other one off axis by approx. 1 meter. This microphone is used for movement detection of the clarinettist in several sections of the work

Special microphones to capture the tam resonances

Ius - sound inputs A

Ius - sound inputs B

Details - loudspeakers configuration

Orchestras amplification

The instruments should be amplifiied locally and in a natural way.

Diffusion of the electronic parts

The sound transformations generated by the computers are spatialized in the halls

For this purpose, independantly from the loudspeakers required for the amplification, the audio outputs from the computers are sent to a set of 12 speakers for room A and 8 speakers for room B. This speakers are located around and above the audiences. For the placement of the speaker, refer to the following pictures

Loudspeaker setup for Room A

Loudspeaker setup for room A

Loudspeaker setup for Room B

Loudspeaker setup for room B

Implantation CGP (A)

Implantation Espro (B)

Install - maxMsp software installation

copy the following folders on the hard disk of both Macintoshes :

Launch MaxMsp

Set the Max File Preferences to point to the following folders

In Max DSP Status, set the I/O Vector Size to 1024, the signal vector size to 512, and overdrive mode is off

Max status

Patch presentation - ius lucis main max patch

There is only one patch for both rooms. We have decided to use exactly the same program on each computer.

This patch (the version used for the premiere was iusLucisConcert126v) has to different configurations. The right configuration can be selected using the menu at the top of the main window

"CGP", meaning "Grande Salle of the Georges Pompidou Center" corresponds to room A

"Espro", meaning "Ircam 's Espace de Projection" corresponds to room B

Ius lucis main patch

Initialization - software initialization check list

On the Mac G5, launch MaxMsp 4.6.3

Open the iusLucisConcert126v patch

Depending on the room in which you are located, select the "CGP" or "Espro" mode

To initialize everything, select the "INIT 0" item on the event menu located at the left of the main main window.

Then select "TEST O" in the same menu.

Turn the DSP on

Ready to go !

Ius main max patch

Patch presentation - ius lucis patch contents

The following picture shows a synoptic view of the signal routing and treatments performed by the computer

Synoptic of ius lucis maxMsp patches

Patch presentation - Spatialisation techniques

Ircam "spatialisateur"

spatialisation vocabulary

Clarinets gesture audio captation

Estimation of the correlation of the sound signals received by two microphones located in front of the musicians

Spatialisation demo patch

Spatius help patch

Patch presentation - rooms resonance modes

To calculate the resonance modes of the rooms, we have used an applet by Paul Falstad

This java applet was ported to a max extern in C called modebox.mxo

Modebox patch

Mode exemple1

Modes exemple 2

Patch presentation - Real Time cross synthesis and convolution

Real Time cross synthesis and convolution

We developped a cross synthesis module in max msp. This module performs a real-time generalized cross synthesis close to the treatment provided by audiosculpt using the pfft~ object.

This module also perform a convolution on the two audio sources. The output of this convolution is then sent to a spectral mapping treatment conntrolled by the "spectral mapping mix" parameter.

It is possible to experiment with this module by opening the 2.ius.cross.demo that can be found in the SpectralTreatments folder.