scaling linear to logarithmic: using slider to control biquad filter cutoff


    Apr 26 2012 | 3:41 pm
    I am wanting to control the cut-off frequency of a biquad filter with a slider or dial. I have noticed that the scaling of a slider to a filter, i.e. [0 127 0.0001 22000], does not work so well as the filter is logarithmic by default. Can anyone advise me on a way around this?

    • Apr 26 2012 | 6:11 pm
      if you can't find the expression [linedrive] might be of help.
    • Apr 26 2012 | 8:01 pm
      [curve] or something like that maybe?
    • Apr 26 2012 | 8:34 pm
      I will try both of those suggestions. Someone told me that to map a 0 127 linear to 0 22000 logarithmic scale you should carry out the equation log127(2200). Does anyone know how I would go about doing this with the expression object?
    • Apr 07 2016 | 10:40 am
      Hi, i am bumping this, because i'd like to control a filter cutoff with a dial.
      Any help with the expression ? i know it's basics of maths and audio, but....
      Thanks !!
    • Apr 07 2016 | 10:42 am
      Well, i found in a tutorial that mtof could do the trick !
    • Apr 07 2016 | 7:19 pm
      that is about what i would suggest.