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Revision as of 09:32, 13 December 2007 by Adnanm (Talk | contribs)

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This project was inspired by the use of feedback as a performance practice by British saxophonist John Butcher.


Normally this practice is done with a simple dynamic microphone and an amp or PA system. My idea is to implement the use of a PD patch as a way of both automatically controlling dynamic volume of the feedback gain and the frequencies selected by a band-pass filter. Another addition to this idea was to have quadraphonic spatilization that is also automatic.


The patch itself is pretty simple and consists of three basic sections:

  1. Feedback loop- set up by two delay lines
  2. Band-pass filters- three filter for each delay line
  3. Spatialization- done by vbap (vector based amplitude panning)


The key object in this patch is the fiddle~ object. It provides frequency and note(midi) information, as well as amplitude data. It can also output several frequency components of the input signal. All of this data provided by the object is used to control the band-pass filters and the vbap variables. The vbap object...does the panning for a variable number of speaker arrays. In this case I used four speakers.