Spatial Audio

The third NIME contribution from the fourMs lab this year was the paper: The ‘Virtualmonium’: an instrument for classical sound diffusion over a virtual loudspeaker orchestra Paper [PDF] Soundfiles Despite increasingly accessible and user-friendly multi-channel compositional tools, many composers still choose stereo formats for their work, where the compositional process is allied to diffusion performance over a ‘classical’ loudspeaker orchestra. Although such orchestras remain common within UK institutions as well as in France, they are in decline in the rest of the world. In contrast, permanent, high-density loudspeaker arrays are on the rise, as is the practical application of 3-D audio technologies. Looking to the future, we need to reconcile the performance of historical and new stereo works, side-byside native 3-D compositions. In anticipation of this growing need, we have designed and tested a prototype ‘Virtualmonium’. The Virtualmonium is an instrument for classical diffusion performance over an acousmonium emulated in higher-order Ambisonics. It allows composers to custom-design loudspeaker orchestra emulations for the performance of their works, rehearse and refine performances off-site, and perform classical repertoire alongside native 3-D formats in the same concert. This paper describes the technical design of the Virtualmonium, assesses the success of the prototype in some preliminary listening tests and concerts, and speculates how the instrument can further composition and performance practice. ...

Interesting things from ICMC 2006 day 6: Matt Wright (CNMAT) talked about CNMAT’s work on augmented guitar and 6-string cello, based on a hexaphonic setup of piezo elements on each string. Mark Zadel (McGill) had an interesting survey of laptop performance. He commented that this type of music is often very dense and with complex soundscapes. Most commercial “live software” are made so that musical elements can be laid out tightly beforehand, and everything is quantized so much that it is impossible to make any big mistakes during the performance. He called this “piloting” systems, where the performer navigates through patches were only a few parameters are open for performance control. ...

Interesting things from ICMC 2006 day 5: Max Matthews (CCRMA) spoke about phase filters The algorithm is a difference equation based on a rotating complex number. A complex number, viewed as a two-dimensional vector, is sometimes called a Phaser, hence the name of the filter. The resulting filter is a high Q two pole resonant filter that is well behaved in terms of stability and is easy to re-tune dynamically during a performance. The filter is about twice as expensive in terms of computer multiplies and additions per sound-wave sample than most other filter algorithms but laptop computers now are so fast that they can run a bank of several hundred Phaser filters in real-time. ...

Interesting things from ICMC 2006 day 2: Tim Place presented Jamoma. Golan Levin presented a very interesting project on spectrographic performance, where a large table with a projected image is “scanned” sequentially and synthesized as a frequency spectrum. So the table would serve as a performance space where physical objects could be moved around to create various rhythmic patterns and timbres. ...