Adjusting oscillator by cents & semitones
  • Hi,

    Just thought this might be helpful for some people. I was trying to figure out the formula to adjust a note by cents & semitones. After some research I found this:

    Cents (where x is the input freq & y is number of cents to step by):
    x*2^(y/1200)

    Semitones (where x is the input freq & y is the number of semitones to step by):
    x*(2^(1/12))^y

    Both of these examples work directly in Audulus. You can connect an Expr node to y to adjust the values. Keep in mind for cents, an adjustment of -100 or +100 is an adjustment of one semitone.

    Hopefully this might make transitioning from 2.0 easier for some :-)

  • Definitely a useful bit of info, thanks!

    It also comes in handy when you're trying to modulate the cutoff Hz of a filter. Modulating the "y" param often sounds better than modulating Hz directly, since you get a lot of movement at the low frequencies, and a lot less at the higher frequencies if you modulate Hz directly.

    A lot of the new stuff is 1/o, mimicking modular synths that map 1 volt to an octave. Modulating by semitones and cents is slightly easier in this case:

    Add y/12 to modulate by semitones, add y/1200 to modulate by cents.