The Fantom of the Ventilation Shaft

Electroacoustic Composition and Performance (P01184) - Commentary

Peter Damon Reid - Digital Composition and Performance MSc

Date: 2006 April 13 - Matriculation Number: 0127815

Course Tutor: Robert Dow



Fantom of the Ventilation Shaft is a seven-and-a-half minute electroacoustic piece for eight speakers arranged in a double diamond configuration. The tracks are supplied on a CD and the track number is denoted by a number suffix to be played on speakers according to the following diagram.

speaker configuration

Programme Note

Secretly circumnavigating the pipes and air conduits that burrow through suburban structures, the restless Fantom of the ventilation shaft darts from one pipe to the next, humming and buzzing, hissing and spitting, blowing and sucking. Flowing all around us, the presence of the Fantom is heard by all, felt by many, known by some and seen by none. The Fantom is mischievous, creeping up and making people uneasy, sneaking inside machines, traversing pipes, riding currents, lurking in eddys, manifesting briefly then vanishing.


The piece was written for eight speakers so that sounds can move around in two dimensions creating an exciting and dynamic sound image in which to immerse the audience. I listened to a variety of electroacoustic music and particularly enjoyed Bernard Parmegiani's La Creation Du Monde. The material in La Creation du Monde is processed so that the source sounds are unrecognizable and can therefore be enjoyed for their intrinsic sonic qualities without being distracted by their real world 'meaning'. I found material with more obvious source material less interesting and took the aesthetic decision to disguise my sound sources.


Source Sounds

In the back of Alison House, home to the University of Edinburgh's Music Department, there is a small toilet cubicle with a ventilation system that produces a rich, slowly evolving, mesmerising drone. Since I noticed its interesting sonic qualities I have wanted to capture its sound and make a piece using it.

I used a rewired electronic toy to generate other pitched sounds. I found a toy guitar with buttons where the frets would be that trigger rock and roll samples. I unscrewed the casing and began using a wire to short different parts of the circuit until I found a point in the circuit that produced a variety of different tones when connected with certain other parts of the circuit. I soldered wires onto all these parts of the circuit with a variable resistor in series with the main wire and soldered a jack plug in parallel with the speaker. Mashing the flying wires together and twisting the variable resistor produces a variety of harsh glitchy electronic tones.

For a less tonal sound I recorded a baby bottle. Sucking the teat produces a long, squeaking and gurgling sound as water rushes out and air seeps in. Releasing the suction lets a flurry of air back through the teat to equalize the pressure. The sound has a nice shape and many subtle nuances. Water is always a very rewarding sound source for electroacoustic composition.

For a contrasting un-pitched sound I manipulated a handful of coins. On a few occasions a few of them fell out of my hand and span around on the desk for a moment before coming to rest. For a more dramatic effect I dropped them all on the desk at once. I was also unable to resist using the tinkling sound of a thrown bunch of keys.

Processing and Arrangement

Sounds were arranged in ProTools with various plugins used to change and disguise the sounds. The piece starts with a short, quiet, glitchy introduction made from the toy guitar as the audience settles down. Then follows a section of heavily bass-boosted toy guitar layered with bottle, coin and fan sounds. The next section begins more gently with fans and bottle slurps before building to a pulsating climax and fizzling out. The next section builds tension with a long fan drone and deep slowed down toy guitar with a tiny bit of coin sound to add interest. The calm finally gives way to an agitated contrapuntal section, then with a final blast, the sound vanishes.

The piece was divided into three sections separated by periods of silence and similar elements in each section were bounced together to be spatialized into eight channels later. This technique allows each element to be given its own place within the sound image independant of the others. The first sections were separated simply into drone and lead tracks. The final more complex section was bounced into drone, toy guitar, coin, bottle and bass tracks.


Custom eight speaker spatialization software was designed in Max MSP. The position of a sound can be specified and moved using a mouse or an analogue style joystick and those movements recorded and saved to file. This technique was used on all the sounds except for the drone. A special algorithm was designed for spatializing the drone sound that plays the sound in eight locations simultaneously and constantly moves a random sound instance to a new random position after a random period of time. The random positions can be constrained to keep the sources all within a tight area or spread over a wider field. The random period can be constrained to a small number so that sounds whizz constantly from one location to the next or to a large number producing a slowly undulating texture. This technique is very effective at creating an interesting, dynamic sound image using monaural source sounds.

Finally, the eight tracks were loaded into ProTools and the levels tweaked to use the full headroom and to create more dramatic dynamic variations.

Final Thoughts

The major commercial sequencers and digital audio workstations don't provide very much in the way of tools for multi-channel work hence why I decided to design some of my own. I found myself working on four channels most of the time and occasionally taking the output to an eight channel system to test the results. The difference between four and eight speakers is quite profound and I found it very exciting to hear my ideas working the way I wanted and occasionally disappointed when they didn't. It was also quite tough having a plan in my mind that would take such a long time to realize. I was sure I would get there in the end if I kept trying and I'm very pleased I did.

Eight channel loudspeaker systems are not very common and nor is music written for them. Electroacoustic music is not people's bread and butter listening material in any case so providing a special experience for the audience is a good thing. In my opinion, good art causes an emotional response in its audience, an engaging experience, whether pleasant or unpleasant. I hope that people will enjoy The Fantom of the Ventilation Shaft and have an exciting experience listening to it.