[29.08.06] Visualising sound with water and light

This afternoon I experimented with making the propagation of a sine wave visible using a shallow amount of water in a cooking tray and a directional light source to capture the wave's movement. As with the bowl piece, I've been using my Marshall amplifier to drive the sine wave, the amp and speaker have been removed from the speaker box as this makes things more convenient. The thing about a cooking tray is that it (at a specific set of frequencies) it resonates quite violently, so not a great deal of volume is required for this phenomena to take effect. This is good as I really want the sine waves to be in the background as much as possible. Though they are part of acknowledging the intention behind this process (sound and vision), the sine waves shouldn't necessarily be the centre of attention, the beauty lies in its interaction with the metal tray, the water and the refracted light. I am thinking of incorporating this into an installation - a darkened space, with four or five of these trays (of various sizes), listeners would be given hand held torches and go around to each of the trays reflecting light off the moving surfaces of the water. The sine waves could also move in cents of frequency (gliss) as this would cause the waves to move and change shape and formation. I'll write more on this soon...

With the setup of speaker, water tray and directional light (amp and oscillator out of shot.) What I'm doing here is trying to move the waves around manually.


Example one: A low frequency resonance (note large bandwidth). The metal tray has many resonant nodes, the complicated formation is due to the waves reflecting off the edges and corners. It would be interesting to see a more pure representation of a single spherical formation - though this is proving difficult to acheive.


Example 2: A much more elaborate formation at a higher frequency with a shallower amount of water. A blue bulb was being used at the stage.

[22.8.06] The Past 2 Weeks

Here's a summary:

[22.8.06] CCSP Research Proposal Presentation

This was a presentation that didn't go badly, but didn't go well either. For a start I was grappling with a change in the direction of the topic (which happened two weeks ago), and had been rushing to put together something plausible. Secondly, I forgot my copy of Lucier's I Am Sitting In A Room, and was forced to explain the process with the audio (which equates to disaster). Finally, I ran out of time and was unable to present the last two components of my research methodology, as well as demonstrate a new work, Songs and Paintings for (a) Metal Bowl(s) [more on this work below]. There were some constructive comments at the end, and for some reason they weren't directed at the apparent holes in my topic at present, then again maybe they were being polite.

[19-20.8.06] Songs and Paintings for (a) Metal Bowl(s).

This is the work that was going to be demonstrated at my CCSP proposal, oh well - perhaps some other time. Here's a technical description:

This a work called Songs and Paintings of (a) Metal Bowl(s). It is a work for a sine wave generator and a metal bowl with a shallow amount of water in it. Attached to the outer base of the bowl is a piezo speaker allowing direct contact with the metal surface. A sine wave which corresponds with the resonant frequency of the metal bowl is played through the speaker thus causing its physical state to vibrate and sound. Because the contact speaker is attached at the centre of the bowl’s base, this creates what is called a node – that is where the amplitude of a wave in a given medium has a value of zero. By tilting the bowl, the water’s edge changes it’s coverage of the bowls base, enabling primary and corresponding harmonic nodes of the bowl to become amplified. The loudest sound appears when the the water’s edge is exactly halfway across the diameter of the bowls base, this represents the first harmonic of the bowl, similar in the way that if you play the 12th fret harmonic of a guitar (exactly halfway along the strings length).

There is no performance process decided upon at present, though two possible outcomes have arisen through a careful examination of the system and it’s relative phenomena.

The first possibility is to allow a performer to explore the sonic potentialities of the bowl by thoughtfully employing different playing techniques, such as tilting the bowl to sweep through its harmonic range. The performer may also sing or project sounds into the bowl, thus causing beating patterns and the amplification of certain waves. Performance could also involve more than one bowl, of different sizes, resulting in an array of contrasting resonances.
(See image below.)


The second possibility is to put the bowl at a fixed position so that the first (and strongest harmonic) of the bowl is sounded. And due to the strong amplitude of the resonant wave - patterns relative to the propagation of the sound wave across the base of the bowl become visible on the surface of the water. With the benefit of a directional light source to refract the wave phenomena, these patterns become more visible and attractive. These patterns could be altered by lowering and raising the frequency of the resonant sine wave by slight degrees – in this case a pitch shifter is ideal for this. For an audience to observe the wave patterns, a video camera could be setup to project the process on a video screen.

[18.8.06] Raoul Valentine plays at the Academy Awards.

A more lighthearted moment came at the Helpmann Academy Awards where I appeared in the rare guise of Raoul Valentine. The girls backstage did a lovely job with the make up as Raoul demanded they make him look respectable. As a cross between Jack Sparrow and Liberace, Raoal sung Tom Waits' 'Temptation' and Leonard Cohen's 'I'm Your Man'. Doing his filthy duty, Raoul took his award and receded like an unforgiving hairline - INTO THE NIGHT.

[10.8.06] Life After Laptop

It has been awhile since I last posted and there is a legitimate reason, my laptop fell into a strange coma last Saturday night and I think it is going to cost me a fair bit to fix. I don't have a fair bit at my disposal at the moment, so that means it is out of action for awhile - So that's pretty legit - the convenience and laziness of wireless internet has prevented me from posting blogs at my usual furious rate. The laptop's demise was a traumatic affair, though I managed to save all of my data. Now I'm stuck with my old G4 box ... oh well - it could be worse.

[1.8.06] Research Progress: Ecotone

Today I didn't have much time to experiement with sine waves, so instead my thought turned to working on an idea for an installation instead. Working under the title of Ecotone, I am interested in constructing an environment where the physical and acoustical properties of resonant objects are effected by variations in temperature and humidity. The term Ecotone relates to a point of transition between two ecological systems, for example think of a rural environment merging into an urban one.

I will set up a series of objects, or vessels if you will, (vases, glasses, cooking trays, etc.) and attach contact mics inside them - one to receive an input signal and the other for the output siganl (a feedback signal will provide sound). Then once the feedback signal (or threshold) is audible and consistent, I will set up an automated temperature/humidity control and let the process and the room do the work. It is going to be a lot of trial and error, but at least this an official point of departure.