spectrum inverting?

    Mar 24 2011 | 9:02 am
    Hi -
    I'm still getting acquainted with the fft~ objects and I was hoping someone might be able to offer some generous assistance in figuring out how to generate an inverted spectrum, within regular audible hearing range - so that frequencies at 0 hz would output at 20 khz, etc...
    I apologize if this is redundant... I feel like there must be a fairly straight-ahead way of doing this..but I don't have much of a mastery of this area yet..

    • Mar 24 2011 | 3:52 pm
      invert the bins...
      It might not sound as you think it should - our hearing range is logarithmic, the bins are not...
      save as spectralinvert~
      and this is to test:
    • Mar 24 2011 | 3:55 pm
      You should also look into vocoder techniques...
      Might sound better than fft...
    • Mar 27 2011 | 11:13 pm
      last year i did an installation at the steim for amsterdams "sonic acts" festival inversing frequencies:
      i wasn´t inverting the raw bins (that sounds dreadful) but using sigmund~ and its track feature and then doing a resynthesis. the remapping of the frequnecies happened there with the help of some scaling.
      this sounded quite good.
    • Mar 28 2011 | 1:09 pm
      or just ringmodulate your sound with mr. Nyquist (no need for fft)
    • Mar 28 2011 | 6:11 pm
      oh my god mr giri your mr nyquist idea is AWESOME! so simple! well for the mere mortals such as i, anyway. THAT should go in mr benson's simple-stuff thread... thanks!
    • Mar 31 2011 | 11:18 pm
      yes its the simplest solution, for sure.
      but sounds ugly as hell :-)
      thats why i choose sigmund~ back then