A Multi-Channel Experiment at Huddersfield University
- Published on Thursday, 24 September 2009 17:01
Housed in the University's new Creative Arts building, SPIRAL (Spatialisation and Interactive Research Lab) will be the centre of research into spatial and interactive music composition, production, and sensoral control.
Professor Michael Clarke (composition, computer music, synthesis/processing software) and Mr Mark Bokowiec (interactive performance systems, electro-acoustic composition, virtual instrument design) are heading up the work that will explore the creative, psychoacoustic, and psychological possibilities of multi-channel audio, as well as the question of how to control the movement of sound in a space.
As a composer and researcher, Clarke has been working with eight-channels for some time now, and has already produced several pieces of 24channel music including the Enmeshed series of works. He sees SPIRAL as an extension to Stockhausen's work with Octophony, which used eight speakers arranged at the corners of a cube, giving two levels of height information, as well as the horizontal plane possibilities.
A 25-channel system is not an easy thing to imagine, much less compose for, so SPIRAL gives an opportunity for experimentation and development of complementary control (routing, panning, effects, and so on) systems. One aim would be to take the medium to a public performance situation: "The advantage of actually having a studio to work in to do this, is that we can learn about how to use this space, how to work with it," says Clarke. "The studio is where people can experiment with different ways of programming for that sort of space, and not just in terms of the acoustics of how you move the sound around, but creatively and psychologically, and psycho-acoustically”.
Spatial control with so many channels is a tricky proposition, as there are many ways to conceive of moving a source around that many speakers. Most of the current work is based in planes. “You could have one wall as one place” explains Clarke. “You could have the ceiling as another, etc, etc. So you can move sound around in that place, then you can move that whole place around to other walls. Then you can go in-between, so you get diagonals going across the room and so on.
“Another way is to think of it being a 3D space – you’ve got one single channel being able to be placed at any point in that space… You could be creating spirals in that space, and moving the source around; then you could have a second channel of sound, which you are also moving around, and the two can dance…. So it’s like a counterpoint, but a counterpoint that involves a spatial interaction as well as melodic.”
Mark Bokowiec, who specializes in control sensors and sensoral control – anything from alternate uses for a Wii to full body sensor performance art, and more - comes into the SPIRAL equation at this point with the physical mastery of the multi-channel space. "We've got quite a lot of esoteric controllers. One of them, which we bought for this space, is called a ‘haptic’ controller." The term 'haptic' refers to control devices that offer physical feedback to the person using them - whether it be resistance, vibration, or any other sensory feedback. In this case it's a 3D controller, rather like an angle-poise lamp.
For the audio bits, the current development tool of choice is Max MSP coupled with flexible RME-based 110. The room features three circles of eight Genelec 8240A monitors, four Genelec 7270A subs, plus an additional height monitor (another Genelec 8240A). Each of the 25 speakers can be fed independently or in groups for detailed control over the sound field inside the space.
The department uses Genelec monitoring throughout its music technology facilities, which include three 'Octophonic' studios, three 5.1 studios, and two stereo rooms with associated live rooms.
Professor Clarke noted: "All our studios are based on Genelec speakers. We are familiar with Genelec and we like the sound – a nice neutral sound, very accurate.”
SPIRAL makes good use of the Genelec Loudspeaker Manager (GLM) control networking system, which offers system parameter control and acoustic alignment for all networked monitors. Clarke: “It's such a beautiful way of doing it… and having it all digital is obviously a big plus point – you’ve got no pick up the cables… the only hum is from the computer”
Paul Mac - Audio Media
This article is published with kind permission from Audio Media magazine and as published in the Audio Media June 2009 issue.