Cut Frequencies for Microphone Feedbacker

    Nov 22 2010 | 6:07 pm
    hey there,
    I'm a max beginner and need some help at an I guess not too difficult question, but I tried for over 10 hours and decided to ask someone who knows better ;)
    I need sort of an EQ in MaxMSP, but not the usual smooth one, that generates curves and stuff. There need to be cut out some frequencies of the audio signal. There should be a gap every 100 hertz. To make it a little clearer I'd like to have 0-100 hz come through, 100-200 to be cut, 200-300 hz come through, 300-400 to be cut and so on, till 44000 hertz i guess.
    Is there a way to do this easily?
    Thanks a lot for your help, i apreciate it

    • Nov 22 2010 | 8:40 pm
      You could try [cascade~], which is like a multiband parametric EQ. But that will be exponential, as opposed to linear, which is what you're proposing...
    • Nov 23 2010 | 7:15 pm
      What you're describing sounds like a comb filter, which could be done with comb~ or teeth~. I'm not sure how satisfying the results would be, though. There's also a 3rd party object called peqbank~. From CNMAT.
    • Nov 23 2010 | 8:41 pm
      I tried already. The problem with cascade~ is that it works exponential as you said. I need something that mutes those frequencies between 100 and 200 hertz completely.
      If been thinking today if it is possible to read a list from the actual audio file, with the values for frequency and the signal that comes through it. And then change the values I don't want to have in the output signal by setting it to zero.
      Is there a possibility to create such a list?
      Thanks for answering so fast wheelersounds
    • Nov 24 2010 | 12:40 am
      fft gives access to a linear scale of frequency bands... have a look at 'forbidden-planet' example (under FFT Fun in the MSP section of the Examples Overview patch found in the Extras menu : )