A special characteristic of electronic music is its medium - the loudspeaker, the so-called sound source, the source of electronic sound. In acoustic instruments, the location of sound production is identical with the location of the sound itself; in contrast, in electronic music these two events occur at different locations. The arising possibility to position sound sources at any location required, thus creating separate sound- spaces in the overall space, promoted the artist's interest in the development of loudspeaker installations. The loudspeakers form a matrix by which sounds are positioned in space or moved through space.

The result is a sounding body which emits music in different states of motion The listener is confronted with virtual sound-spaces, their specific character being the real three-dimensional movement of sound. The spatial sound movement emerges as a significant component in the conception of music, furthermore structuring the course taken by the composition.

In chapter 4 you will find my essay entitled "The Spiritual Location of Sound - an example for the integration of sound movement as a fourth parameter in the composing process". This essay tells about the way the new possibilities offered by the three- dimensional movement of sound in space affect the spiritual process of composing.

Three-dimensional sound movements require substantial hard- and software, which has been especially conceived and built by Sukandar Kartadinata. In the course of the past few years he has realized the technical work on the project. More detailed information on the technical performances is to be found on the following pages.

The sound distribution systems are controlled digitally. Up to eight acoustic signals may be moved over sixteen or twenty-four individual outputs. Thus several sound layers perform different movements at the same time. On the following page you can see a sketch demonstrating the movements created by a curved structure made up of seven loudspeakers. More detailed information on the technical developments is given in the article by Sukandar Kartadinata entitled "The Topoph24".