Electrophonic Box Series
Inspired by the eclectic experiments from the pioneering days of electronic music, and desperate to move beyond walnut veneer chipboard, Matthew Hoare has developed the Electrophonic Box Series, a set of five automated, electro-mechanical instruments producing electronic music without the use of loudspeakers. clatterbox caught up with Matt Hoare to find out more about his Electrophonic instruments.
Aside from exposed large sub-woofers pumping out fat bass lines, the vibratory movement of most loudspeakers is visually fairly imperceptible to the listener. Besides, is it worth running the risk of finding a brown note or liquifying your insides simply to glimpse a boofy sub-woofer diaphragm pounding away? Maybe. But why shouldn’t loudspeakers, or other sound producing devices, be designed to appeal to more than just our sense of hearing? After all most musical instruments are designed to be both a visual piece as well as tools for producing sound, so why not loudspeakers? And how might electronic music be produced and conveyed without using conventional loudspeakers?
Matt Hoare set about developing this series of instruments to provide examples of possible alternatives for producing electronic music. As Matt Hoare points out, his inspiration for developing these instruments was borne out of the experiments undertaken by the pioneers of the electronic music in the early part of the twentieth century.
Mini-Speaker Music
Mini-Speaker Music is designed to appeal to people both aurally and visually. Placing polystyrene balls in perspex tubes over loudspeakers enables you to use sound signals to make the polystyrene balls dance. The balls act as a visual indicator to the vibrations being produced by the instrument. The only predictable behaviour of the balls is that they will leap into action when the speaker starts to vibrate and will remain active until the speaker comes to rest.
The instrument is tuned to seven-limit just intonation, with all of the frequencies derived from the lower part of the harmonic series. After watching the instrument play for some time it becomes clear that particular frequencies cause the polystyrene balls to bounce higher than other frequencies.
Little Light Music
While soldering components to a circuit board one day, Matt Hoare noticed that the surplus protruding ends of the component’s leads, the bits usually cut off to neaten up the board and prevent short-circuits, resonated when gently plucked.
From this discovery Hoare decided to construct an electro-mechanical instrument completely self-contained on a circuit board, with only the power source attached. Has Hoare points out ‘… electronic music made entirely by one circuit board with nothing else attached is something you never come across. The real appeal of this approach is the immediate connection between the electronics and the music. The instrument is the electronic circuit board.’
The electronics are actually playing the leads of their own circuit. The circuit produces sound when a current passes through the small coils that in turn (electro-magnetically) pluck the positive leads of the little lights (LEDs), which glow as their leads are plucked.
In deciding what the instrument would actually play, Hoare decided not to program in pre-determined sequences of music. Instead the instrument’s electronics incorporates a digital logic process to determine the rhythm and structure of the music in real time. The sequence of notes is determined by a psuedo-random sequence – a mathematical pattern calculated by electronic logic gates. The pattern is calculated in real time, not programmed, and yet what will be played is predictable.
Spark Music: a homage to thunder
The most direct way of converting electricity into sound is by making sparks. By directing an electric charge from the negative terminal of a high voltage power source, via a conductor, to within millimetres of the positive terminal, the charge will short circuit through the air. The resulting spark rapidly heats the air and creates an omnidirectional shock wave. This shock wave is audible as a bright ‘snap’.
The Spark Music instrument puts these sparks to musical use. High voltages are generated by small transformers wired back-to-front to produce pulse waves of various frequencies. Subsequent sparks or ‘snaps’ are generated in quick succession, up to 12,000 times per second, to produce the various pitches.
Matt Hoare describes Spark Music as ‘… an attempt to make pure electronic music. Sound literally made by electrons… a homage to thunder’.
Similar to Mini-Speaker Music, Spark Music’s harmonic sequence is a progression in seventh-limit just-intonation, with all intervals derived from the harmonic series.
It should also be pointed out, before you surreptitiously reach out for a pluck and fidget, that Spark Music is strictly a hands-off automated instrument. While the instrument’s high voltages are not accompanied by significant electrical current, if touched the sparks will give you a nasty shock.’
Relay Music
Relays, an electro-mechanical switch, are one of the few components commonly found on electronic circuit boards designed to produce sound.
Common relays consist of a coil of wire around a ferrite core, and a small flat piece of steel suspended above the coil with springs. When the relay is switched on, the piece of steel is attracted toward the coil, closing the contacts, and thereby allowing a larger current to flow through the contacts. In many relays this process produces a clicking sound.
Relay Music is an instrument for making music with a set of 18 relay switches. Set at different frequencies, the relays produce a wide range of clicks, pitches, and timbres.
Switching individual relays at frequencies higher than 5,000 Hz (hertz) produces smooth pitches, and the resulting tone is surprisingly pure. Switching individual relays at frequencies between 100 Hz and 3,000 Hz produces coarse sound textures, which are also surprisingly loud. Switching individual relays at frequencies below 100 Hz enables the ear to hear the individual pulses, or clicks.
Similar to the other instruments in the Electrophonic Box Series, Relay Music’s harmonic sequence is a progression in seventh-limit just-intonation.
Motor Music
As Matt Hoare suggests ‘… grab an electric motor, attach a load to it, and your motor becomes an electric musical instrument.’
A standard electric motor comprises an electric coil and a magnet. Every time the electric coil is switched on, in the vicinity of the magnetic field, a click will be heard. These clicks can be used as raw material for producing sound waves. In terms of the Motor Music instrument, pulse waves are produced.
In order to produce a clear pitch, each motor must be turned ON and OFF hundreds of times per second, with some motors switching up to 5,000 times per second. It follows then that the frequency of the pitches is determined by the rate of each motor switching (i.e. how many clicks per second); and the timbre of the pitches is altered by varying the regularity between these switches.
Similar to the other instruments in the series, Motor Music is tuned to a harmonic progression in seventh-limit just-intonation.
closing note
The Electrophonic Box Series instruments offer us some intriguing alternatives that will hopefully inspire and encourage others to explore these alternatives as part of the revival that Matt Hoare predicts ‘… I think it’s inevitable that the diversity in approaches to electric music of the late 19th Century will be rediscovered and further expanded as people become aware of the limits of the loudspeaker.’
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