i m m e r s i o n   2 Immersion 2 comprised three concert programs of electroacoustic music to demonstrate the theory and practice of live surround sound spatialisation. A 24-speaker Acousmonium or 'speaker orchestra' was especially constructed for the presentation featuring assorted loudspeakers positioned in and around the audience. Technical characteristics such as amplitude, frequency response and dispersion pattern, proximity of loudspeaker to audience, as well as the acoustics of the performance space determined the position of each loudspeaker in the auditorium. A live mix strategically drew upon each loudspeaker to create specific zones of activity, as well assigning various combinations of loudspeakers to articulate complex spatial gestures. RMIT Storey Hall was selected as the site of performance because of its overall size, acoustic character, and its flexible and modular seating arrangement. As the audience must be placed inside a matrix of loudspeakers, the space has to be large enough to accommodate the range of loudspeakers positioned throughout the auditorium so that listeners receive an evenly distributed sound mix. If they are positioned too close to any one particular loudspeaker or group of loudspeakers, they will receive a distorted sound image by one part of the matrix being more dominant than the other. For the performers to also receive an even three-dimensional sound image, they are usually located in the centre of the auditorium so that they can accurately monitor and shape their live mix.
		Therefore to locate audiences within the loudspeaker matrix, and around the live performers demands a venue that is flexible in the way it can be set-up. The concert series comprised historic and contemporary works drawn from the Groupe de Recherches Musicales (GRM) spanning a 50-year period, as well as contemporary Australian electroacoustic music. Based in Paris, the GRM are at the forefront of research into the relationship between music, perception and technology in the development of new methods of composition and performance. It has made significant contributions to the field of experimental music that includes the development of musique concréte, as well as pioneering research into psychoacoustics, synthesis, digital signal processing and sound spatialisation. The GRM continues to be actively engaged in the dissemination of electroacoustic music through education, research, broadcast, publication, archival preservation and concert presentations. Immersion 2 provided the first opportunity for the GRM to demonstrate aspects of their most significant research in Australia.