Reverberation is very important for the sound quality in indoor spaces. Listeners gladly hear rich reverberations that enter the left and right ear at different moments. Just as light is concentrated with a hollow mirror, so too can sound be joined by means of the partition of an ellipsoid. This test form appears on the scale of a large half egg, with two focus points. The one focus point, with the flutes, can be found in the scale and the second one is positioned at the front. Flute sounds reflect from the first focus point by means of the bent partition to the second one. Because the flutes are reverberated by means of each point on the scale, the reverberating sound comes from all sides and arrives at that second point. As a result, there is no perception of direction; sound simply exists, concentrated in a globule. So it seems as if the flute sound is made in the listener's head. This sound globule is a new transmitting point. As soon as the listener stands in the focus point, sound is reverberated 'from' his/her head to other spectators. Perplexing is that those bystanders think that the sound comes from the head of that listener.

It is all about disorientation of eyes and ears in this structure, creating a hallucinating effect. Function dictates form. Purity and simplicity are the most important impressions. The clean, set form has been radically processed. A 'sound machine', a computer-controlled `ensemble' hangs high above in the Klankkaatser, at one focus point (of the ellipsoid). The sound machine contains a fan which transmits varied wind thrusts to five bamboo flutes, so that those flutes play composed music. The flutes vary slowly in loudness, pitch, timbre and tempo by the use of variable wind pressure, variable nodes and `tempo valves'. These are enriched sounds, with high pitched noise and double tones. The interaction between the flutes creates all kinds of floating effects and changes in tones. These live sounds are reverberated by means of the entire hollow inner wall and connect to the other focus point, at ear level, inside your head. There are also slight changes of colour and intensity. This happens subtly, barely noticeable. Since you cannot focus on the bent partition which has no angles or lining, you experience above 'above your head an 'infinite' space, a Ganzfeld. In this situation light appears to be a floating, powdery substance. Like smoke, like matter. The lighting, hundreds of LED bulbs which can produce all colours, has been composed together with the sound. If that occurs correctly, a small wonder arises. Then sound and image coincide and intensify each other' The atmosphere in the Klankkaatser is sober, subtle and intense. No spectacle, no sensation, but concentration and contemplation. A minimum of actions, a minimum of resources: simplicity. Therefore minute light, minute sound: tranquillity. And wonder instead of surprise. Compare this to a chapel or a small temple, where the public can step in from their everyday life and come to some introspection. The Klankkaatser has an effect on the senses. It relates to those sensations which arise by intensifying sensual experiences and by connecting these experiences. The public is also confronted in the Klankkaatser with an individual manner of looking and listening, and the perception of how people look and listen. This all assembles in the Klankkaatser, all aspects work together in the completion of the work: it is sculpture, it is sound, it is composition, music. It is architecture, it is public and private. (drawing Farhan Alibux)

Sound Machine from the 'Klankkaatser'
It is hanging in top of the structure, not visible for the eye of the visitor.





foto Reyn van Koolwijk