The Springboard by Eric Leonardson

Springboard contact microphone Eric Leonardson
The Springboard is made from everyday objects, such as a tin can lid, spring coils, pieces of wood and combs. © Eric Leonardson

Eric Leonardson invented his Springboard in 1994. This instrument is an excellent example of how the simple addition of a contact microphone can create a beautiful sonic phantasmagoria out of ordinary objects. When you look at the instrument, you can see all kind of familiar objects such as pieces of wood, combs, coil springs, a metal grill, a tin can lid and large rubber bands. The sounds produced by these ordinary objects are often of a surprisingly complex and varied nature. When listening to a recording, it is difficult to recognise the source of the sound and without any visual cues it often remains a mystery, which object produced which sound. This recording of a concert with the Springboard in 2012 gives an impression of a composition developed from the sonic possibilities of the instrument:

The contrast between sight and sound is mainly created by using a single contact microphone for amplifying all sounds produced by this instrument.  The main part of the instrument is a simple piece of wood. As the drawings by Eric show, there is a hole drilled in this board for a recessed mounting of the piezo disk. An older hole (see previous cable in the first drawing) is not in use anymore. As Eric explains: “I originally drilled into the end of the board so I could pass audio cable into the recess, similar to how a solid body electric guitar connects its coil to a jack. On the Springboard, the cable was soldered to a standard 1/4-inch jack and to the contacts of the piezo disc, inside the board. I abandoned that system because whenever I performed on the Springboard with more forceful percussive rhythmic pattern, the shaking would cause the audio plug to jiggle and momentarily break the connection, hence the audio output would be interrupted.”

Top view of the contact microphone mounted on the Springboard. Drawing by Eric Leonardson, © Eric Leonardson
Top view of the contact microphone mounted on the Springboard, the previous cable whole can still be seen. Drawing by Eric Leonardson. © Eric Leonardson


A cross section view of the mounting of the piezo disk on the Springboard. Drawing by Eric Leonardson. © Eric Leonardson
A cross section view of the mounting of the piezo disk on the Springboard. Drawing by Eric Leonardson. © Eric Leonardson


The contact microphone attached to the board. © Eric Leonardson
The contact microphone attached to the board. © Eric Leonardson

Since the contact microphone is amplifying the mechanical vibrations of the object itself, the amplified sound is filtered more than in other forms of amplification. Contact microphones give you a different sonic perspective of an object, without changing their visual characteristics. As Eric phrases: “Its ability to act as an aural microscope into unknown sonic yet entirely physical aspects of any object or material is truly exciting, if not amazing” (see The Springboard: The Joy of Piezo Disk Pickups for Amplified Coil Springs). He did not really plan to invent an instrument, but he was just looking for “a simple device for amplifying readily available objects and materials, producing a wide range of extraordinary sounds, in a way so tactile and immediate that the Springboard lent itself as easily playable” (see Eric Leonardson’s website on his Springboard, including information on all objects he uses and how to make a similar instrument yourself). But as it turned out, his search for sounds resulted in a musical instrument nonetheless.

The contact microphone seems to have initiated a process of exploring all possible sounds. The richness of the instrument is not depending of the objects themselves, or the simple method of amplification, but of a very intense investigation of all different sonic possibilities of the everyday objects used. What makes this instrument so special, is not the material itself, neither the form of amplification, but the playing techniques Eric developed: “I seldom ever hit any parts of the instrument as one hits a drum. Instead, bows, brushes, friction mallets, chopsticks, my bare hands and fingers apply controlled pressure, flexion, and friction to produce its most intriguing sounds. […] As with a stringed instrument, bowing produces a harmonically richer tone than plucking a string.”

Although nearly all sounds are produced solely by contact microphone amplification, there are a few exceptions. As you can see and hear in this documentation video of the Springboard by Joshua Baum, around 3’04” the small music box is amplified by placing it on the board and with the help of an effect pedal its sound is transposed. Musically, the use of the effect pedal seems to be an enlargement of the coloured amplification by the contact microphone: the transposition is a sonic development of the filtering caused by the amplification.

Another element is Eric’s use of the reversibility of microphone and loudspeaker technologies. In this case, he uses another piezo disk, but connects it to the output of a small radio. This piezo disk now functions as a kind of tactile transducer, and can transmits its vibrations to the objects it touches. By placing it upon one of the objects of the Springboard, this object starts to vibrate, and these vibrations are amplified by the contact microphone. This effect can be heard around 3’24” in the video above. Eric uses the tactile transducer as a kind of very special mallet or bow, being able to play his instrument in yet another way. In the next video Eric explains some of his playing techniques:

Eric is regularly performing with other musicians, and one of them is Birgit Ulher, who is using loudspeakers as a trumpet mute. In this video their performance as a duo starts at 40′:

Fifty years of loudspeakers and ping pong balls

Some objects seem particularly suitable to be used for preparing loudspeakers. The lightness and characteristic sound of ping pong balls might be a reason, why they have been favourable objects for this. Comparing several of these set-ups reveals that—fortunately!—using a similar technology can still result in completely different works.

Loudspeakers ping pong balls
Leser 1 by Manfred Mohr and Jochen Gerz. The loudspeakers and ping pong balls are covered by a large transparent plastic bag. Polyester tube, 19 loudspeakers,  printed transparent plastic bag, 19 moving ping pong balls, electric motor, 180 cm x 45 cm, 1967 Source: © Manfred Mohr and Jochen Herz

As far as I know, the first work using ping pong balls in combination with loudspeakers is Leser 1 (1967) by Manfred Mohr, who created the audio sculpture, and Jochen Gerz, who wrote the text for this installation. This  tower contains 19 loudspeakers, each prepared with a single ping pong ball and was exhibited for the first time in 1968 in Paris. The audience can press a foot pedal to turn the installation on for a minute. Three different frequencies are then played through the loudspeakers and causing the ping pong balls to move away from the loudspeaker membranes and hit the plastic bag (see also the scheme at the end of this post). The ping pong balls are alternating between striking the plastic bag and the loudspeaker membrane and the combination of 19 ping pong balls making this movement produces a noisy sound. Together with the text printed on the big plastic bag and a random letter printed on each ping pong ball the whole installation seems to make an attempt to speak. The text itself seems also to be related to the movement of the ping pong balls: the big letters in the middle read: “Auf Flüchtlinge wird [ge]schossen”, which could be translated as “shoot the people fleeing”. Manfred Mohr explained me, that this text refers to the fact that at that time the East German police had the order to shoot the people fleeing to West Germany.

In Music for Pure Waves, Bass Drums and Acoustic Pendulums (1980) Alvin Lucier uses four bass drums and places them in front of four loudspeakers. A low sinus sweep is played through these loudspeakers and the membranes of the bass drums start to vibrate, according to their resonance to the frequency of the sinus wave. In front of each drum a ping pong ball is hanging from the ceiling, just touching the drum head. The vibrations of the skin push the ping pong ball away from the drum. Depending of the moment of hitting the drum, when the ball falls back, as well as the direction and amount of vibrations of the drum head, the ping pong ball will be pushed away next time with more or less force. Although the set-up seems to be four times the same, the results of the small differences in material of bass drum, loudspeaker and ping pong ball can be clearly perceived in the movement of the ping pong balls and the resulting sound. The shape of the ping pong balls reminds me of the head of a drum stick, and these drums seem mysteriously “played” by the ping pong balls.

Christian Skjødt uses 16 loudspeakers and an equal amount of ping pong balls in Inclinations (2016). Here again each loudspeaker with ping pong ball combination creates its own rhythm, but due to the ping pong balls moving in upwards direction they fall down much faster than in Lucier’s set-up. This causes a constantly changing, soft and noisy rumbling. Christian is not using any other material such as a plastic bag or drums. Since the frequencies played through the loudspeakers are too low for humans to be heard, all sound is produced by the collisions of ping pong balls and loudspeaker membranes. The minimal visual quality of this installation underlines the focus on these sonic events.

loudspeakers ping pong balls
The three different relationships between ping pong balls and loudspeakers, from left to right: In Leser 1 the ping pong ball hits the loudspeaker and the transparent plastic bag. In Music for Music for Pure Waves, Bass Drums and Acoustic Pendulums the loudspeaker just hits the drums. In Inclinations the ping pong ball is placed directly on the loudspeaker.

After I finished this post on loudspeakers and ping pong balls, Ricardo Arias brought the piece PingRoll (1997) by Manuel Rocha Iturbide to my attention:

And João Ricardo mentioned Kugel-Percussion (2006) by Peter Vogel to me:

loudspeaker ping pong ball
Kugel-Percussion by Peter Vogel, with one ping pong ball and one loudspeaker © Peter Vogel

And another addition: When preparing my text on Sound in a Jar I bumped into another piece of Ronald Boersen, using loudspeakers and ping pong balls, called talk to me… . The ping pong balls are hanging in front of a tam-tam . You talk into a microphone and see and hear your speech reflected in the movement of the ping pong balls. To achieve this, the voice is processed in the computer, attenuating resonating quality in the speech, that maximises the response of the resonating frequencies of the tam-tam. This sound is than diffused through a tactile transducer attached to the tam-tam. The ping pong balls start to move due to the tam-tam vibrations, creating sounds themselves as soon as they hit the tam-tam: