The SoundSaber is a musical instrument based on optical marker-based motion capture technology. The instrument demonstrates how a quite simple synthesiser can be quite intriguing to interact with, especially when the mappings between motion features and sound features is well designed.
The SoundSaber controller is a rod roughly 120 cm in length with a diameter of 4 cm. Four markers are placed on one end of the rod, and the motion capture system recognizes these as a single rigid object, tracking position, and orientation of the tip of the rod. The rod is heavy enough to give it a reasonable amount of inertia and, at the same time, light enough to not feel too heavy, at least not when it is held with both hands. The shape and mass of the rod also make it natural to perform large and smooth actions.
The SoundSaber synthesizer is implemented in Max/MSP. A pulse train (a sequence of impulses or clicks) with a frequency of 1000 Hz is sent through two delay lines with feedback loops. The delay times for the delay lines can be adjusted by the user, resulting in variations in harmonic content. Furthermore, the output from the delay lines is sent to a ring modulator where a sinusoidal oscillator modulates it. The user can control the frequency of this oscillator in the range between 40 and 100 Hz. The ring modulated signal and the output from the delay lines are added together and sent through an amplitude control, another feedback delay line, and a bandpass filter where the user controls bandwidth and frequency.
Various low-level features, such as absolute velocity, horizontal velocity, pointing angle, etc., are calculated and mapped to the control parameters in the synthesizer. More details on the instrument can be found in a SoundSaber paper presented at NIME 2011.
The SoundSaber has been presented in posters and oral presentations at various national and international research conferences:
- Jensenius, Alexander Refsum; Glette, Kyrre Harald; Godøy, Rolf Inge; Høvin, Mats Erling; Nymoen, Kristian; Skogstad, Ståle Andreas van Dorp; Tørresen, Jim. fourMs, University of Oslo – Lab Report. International Computer Music Conference, New York, 2010.
- Nymoen, Kristian. Motion Capture: Motion Analysis and Musical Instrument. VERDIKT Conference. Oslo, November 2011
- Nymoen, Kristian; Skogstad, Ståle Andreas van Dorp; Jensenius, Alexander Refsum. SoundSaber - A Motion Capture Instrument. The International Conference on New Interfaces for Musical Expression. Oslo, May 2011
Furthermore, various SoundSaber demonstrations and installations during events at the University of Oslo and elsewhere, including:
- Workshop on Motion Capture in Music, fourMs Lab, University of Oslo. 12. October 2009
- Dagen@IFI, University of Oslo. 29. October 2009
- Open lab, fourMs, University of Oslo. 4. March 2010
- Art.on.Wires Festival, Kanonhallen, Oslo. 10. May 2010
- Open lab, fourMs, University of Oslo. 20 August 2010
- Dagen@IFI, University of Oslo. 28. October 2010
- Motion capture workshop. International Conference on New Interfaces for Musical Expression, University of Oslo. 28. May 2011
- Installation during the opening month of the new informatics building. Ole Johan Dahls hus, University of Oslo. 1.-30. September 2011
- Idefestivalen om Digitalisering, Frederikkeplassen, University of Oslo. 17. September 2011
- Dagen@IFI, University of Oslo. 27. October 2011
- The International Summer School in Systematic Musicology (ISSSM 2012), University of Hamburg. 10. August 2012
- The International Conference on Field Programmable Logic and Applications (FPL), University of Oslo. 29.-31. August 2012
Download the SoundSaber Max patches.