The IKO (icosahedral loudspeaker) is a compact playback device that uses acoustic algorithms to project sound beams into freely adjustable directions, including walls reflecting the sound beams to the listener.

In the existing compositions, listeners perceive auditory objects that move away from the IKO and can have various shapes. The auditory objects hereby created are stunning, maybe because they involve a natural contribution of the space.

Moreover, the visual simplicity of the IKO is contributing to an intimate and focused listening atmosphere. Nevertheless, how the effects work depends on how the sound beams are configured and mixed, as well as the space situation. For this reason, spatial compositions require to be adapted to the acoustic reflection paths in the given situation, unless the setup is strictly prescribed.

IKO is suitable as a versatile electroacoustic composition tool as well as a concert instrument playable in both chamber music halls and larger concert halls. This requires bringing together factors including loudspeaker system, computer, beam-forming, room acoustics and the audience’s perception as a cohesive unit of factors within the composition and intensively keeping eyes and ears on the interactions within the compositional process.

More information:

Gerriet K. Sharma, ‘Orchestrating Space by Icosahedral Loudspeaker (OSIL)‘, Research Catalogue (2021) https://www.researchcatalogue.net/view/385081/945383/38.5/38.5


The 3-9-3 loudspeaker was developed at the Institute of Electronic Music and Acoustics (IEM) Graz by Stefan Riedel as a "DIY-downgrade" of IKO and researched in a joined project by scientists Dr. Franz Zotter, Dr. Matthias Frank and Dr. Gerriet K. Sharma in 2019. The project was funded by an artistic research grant by the county of Styria/Austria.

Meanwhile, spaes  developed their own amplification and owns two 393 prototypes that can be used in all kinds of media installation setups and concert situations yet to be explored.

By producing very narrow sound beams the 3-9-3 loudspeaker projects phantom sound sources onto reflective surfaces so that the listener perceives sound mostly situated at and coming from coordinates at walls, floors, ceilings and the like and only occasionally from the visual objects of the loudspeakers. Sound becomes a plastic spatial event sculpturing artifacts as sonic planes projected onto other planes, causing decoupled zones of intensities (E. Varèse, 1930). The definition of these places is therefore in a recognisable yet constant reconfiguring process.

Spherical loudspeaker arrays:

3-9-3 paper on Research gate: