Theremin

[Paul Perry]

this is part of a post from Miha Tomsic <miha.tomsic at guest.arnes.si>
who used to be on this list... it seems so promising for a 'cheap &
completely different' alternate controller that I asked could i post it here..
and here it is (those ultrasonic things are very cheap BTW)

>When I was working on my diploma (Diffraction of ultrasound on zone plate)
>i ran into an interesting phenomenon. 
>I am using the setup with cheap piezo ultrasound transducer (@40kHz) and
>receiver. The ultrasound is very well reflected from all hard flat
>objects and it interferes coherently. So when I am moving objects around
>the transducer/receiver pair I get amplitude modulation of the 40kHz
>carrier in the range of sonic and subsonic frequencies. The object can be
>the palm of my hand, my body, notebooks... anything really. Quicker
>motions give me higher modulation frequancy and the distance from the t/r
>pair give me shallower or higher modulation. 
>I only need to follow the envelope and I get a nice "bass machine". I am
>wandering how it would sound like. 
> - Miha Tomsic --- C. na postajo 55 -- SI-1351 Brezovica pri Lj. --- SLOVENIA -
> - home-made -- electronics -- music -- industrial -- physics -- net -- linux -
> - phylosophy -- poetry -- arts ---- Lower Parts of Abdomen ---- Josef Banale -
>
relayed by paul perry melbourne australia