4 Band EQ: how to made?


    Apr 21 2009 | 5:23 pm
    Hello, i'm new user of Max MSP.
    I'm trying to make a 4 band parametric EQ but i'm not able to do it.
    I find and watch che object filtergraph with cascade method but i don't understand how i have to use for my 4 band eq.
    I want made an eq with parametres changed by knob (like an hardware eq [but with graphic rappresentation]) or by mouse modifing che values in graph (like a software eq [eq in logic, pro tools, etc..] ).
    If you could help me I would be grateful because I don't understand...
    ps. sorry for my bad english in post

    • Apr 21 2009 | 6:15 pm
      Here's a start using cascade~.
    • Apr 21 2009 | 6:33 pm
      You will probably want to use peaknotch rather than bandpass filters for the middle two [filtergraph~]s. This can be changed from the object inspector.
      lh
    • Apr 21 2009 | 7:50 pm
      Holland Hopson wrote on Tue, 21 April 2009 20:15Here's a start using cascade~.
      what you mean?
      I don't understand how to make the 4 band... 1 band (1 filter [bandpass, lowshelf, peak etc] it's ok, but i don't understand how to make 4 band.
      I read the cascade~ object and biquad~ object but i don't understand very well how them working, above all the biquad~ object...
      Thanks a lot
    • Apr 22 2009 | 5:53 am
      in case you wonder how to use the filtergraph for more that one biquad, this is not possible. you can only use it for displaying a curve of more than one set of coefficients. if you are building a fixed frequency eq you can easily use a transparent pictslider object for Q and gain by putting it over the filtergraph, if you build a normal eq this is too difficult and your best bet are additional sliders and knobs beside the graph.
    • Apr 22 2009 | 8:43 pm
      Roman Thilenius wrote on Wed, 22 April 2009 07:53 in case you wonder how to use the filtergraph for more that one biquad, this is not possible. you can only use it for displaying a curve of more than one set of coefficients. if you are building a fixed frequency eq you can easily use a transparent pictslider object for Q and gain by putting it over the filtergraph, if you build a normal eq this is too difficult and your best bet are additional sliders and knobs beside the graph.
      I want to make a parametric eq, not with fixed frequency. i don't understand the object [biquad] and how i can use the pictslider over the filtergraph.
      An example' patch of 4 band eq is not possible to find or see on the internet? I want to study how to male this eq, is not for commercial-work or similar... only personal study
    • Apr 22 2009 | 9:21 pm
      Shama, Here's an expanded version of the patch I posted previously. I've included another UI approach using the nfilters message to filtergraph~. Hope this helps.
    • Apr 22 2009 | 9:37 pm
      shama wrote on Wed, 22 April 2009 22:43 I want to make a parametric eq, not with fixed frequency. i don't understand the object [biquad] and how i can use the pictslider over the filtergraph.
      biquad~ IS a difficult object, but still better than FIR filters based on transfer functions, because you have to program those yourself.
      i attach a simple EQ of mine. it has 3 bands, and uses the filtergraph object to calculate the coefficients for biquad. then it displays the result of all three filters in another filtergraph. typically setup will put filters in a series, then disallow crossing the freqeuncy settings. sometimes parallel biqads also make sense.
      if you want to add Q control you will find out yourself how it works, just look how i did it for the frequency.
      this patch is not perfect but probably better for you than the biquad helpfile.
      -110
    • Apr 26 2009 | 3:51 pm
      Many thanks at all, i make this eq, i'm testing it now!
      I help myself with che tutorial "guitar processing", where there's an eq!
      Roman Thilenius, your eq is beautiful but it's complicated for my to understand... many objects i don't know well..
    • Apr 27 2009 | 8:50 am
      You would want to use cascade~ not biquad, or look into svf~ This is for studying:
    • Apr 27 2009 | 10:01 am
      Roman, the 110.OLS-i-3 abstraction is missing. Love the Koblo look, btw, cheers Roger
    • Apr 27 2009 | 1:30 pm
      roger.carruthers wrote on Mon, 27 April 2009 12:01Roman, the 110.OLS-i-3 abstraction is missing. Love the Koblo look, btw, cheers Roger
      oops..
      you probably also noticed that this -25 +25 seems somehow wrong... and yes, it is.
      i bought some webspace yesterday so i can re-up the 2007 collection soon.
      -110
    • Apr 29 2010 | 4:41 pm
      all that mass of long text - how do I get that into max to look like a patch?
    • Apr 29 2010 | 5:09 pm
      Check the Common Max Arcana thread: https://cycling74.com/forums/common-max-arcana
    • Apr 29 2010 | 7:03 pm
      thanks - sorry, common posting, but couldn't find it. All works, cheers!