HelpSource/Tutorials/Mark_Polishook_tutorial/14_Subtractive_synthesis.schelp

   1 title:: 14_Subtractive_synthesis
   2 summary:: Mark Polishook tutorial
   3 categories:: Tutorials>Mark_Polishook_tutorial
   4 related:: Tutorials/Mark_Polishook_tutorial/00_Introductory_tutorial
   5
   6 section::Filtering
   7
   8 The basic idea of subtractive synthesis is similar to making coffee: something goes through a filter to remove unwanted components from the final product.
   9
  10 section::The .dumpClassSubtree message
  11
  12 Get a list of ugen filters in SuperCollider 3, by sending the .dumpClassSubtree message to the Filter class, as in
  13
  14 code::
  15 Filter.dumpClassSubtree;
  16 ::
  17
  18 ( code::Object.dumpClassSubtree:: prints all SuperCollider classes)
  19
  20 ////////////////////////////////////////////////////////////////////////////////////////////////////
  21
  22 classtree::Filter
  23
  24 ////////////////////////////////////////////////////////////////////////////////////////////////////
  25
  26 Use LPF, a low-pass filter to subtract high-frequency content from an input source.
  27
  28 code::
  29 (
  30 SynthDef("subtractive", {
  31         Out.ar(
  32                 0,
  33                 LPF.ar(
  34                         Pulse.ar(440, 0.5, 0.1),        // the source to be filtered
  35                         Line.kr(8000, 660, 6)           // control the filter frequency with a line
  36                 )
  37         )
  38 }).add;
  39 )
  40
  41 Synth("subtractive")
  42 ::
  43
  44 ////////////////////////////////////////////////////////////////////////////////////////////////////
  45
  46 RLPF, a resonant low-pass filter, removes high-frequency content and emphasizes the cutoff frequency.
  47
  48 code::
  49 (
  50 SynthDef("passLowFreqs2", {
  51         Out.ar(
  52                 0,
  53                 RLPF.ar(
  54                         Saw.ar([220, 221] + LFNoise0.kr(1, 100, 200), 0.2),
  55                         [LFNoise0.kr(4, 600, 2400), LFNoise0.kr(3, 600, 2400)],
  56                         0.1
  57                 )
  58         )
  59 }).add;
  60 )
  61
  62 Synth("passLowFreqs2")
  63 ::
  64
  65 ////////////////////////////////////////////////////////////////////////////////////////////////////
  66
  67 Resonz is a very, very, very strong filter. Use it to emphasize a frequency band.
  68
  69 Transform noise into pitch with a sharp cutoff.
  70
  71 code::
  72 (
  73 SynthDef("noiseToPitch", { arg out = 0, mul = 1;
  74         Out.ar(
  75                 out,
  76                 Resonz.ar(
  77                         WhiteNoise.ar(mul),
  78                         LFNoise0.kr(4, 110, 660),
  79                         [0.005, 0.005]
  80                 )
  81         )
  82 }).add;
  83 )
  84
  85 (
  86 // activate left and right channels
  87 Synth("noiseToPitch", [\out, 0, \mul, 1]);
  88 Synth("noiseToPitch", [\out, 1, \mul, 1]);
  89 )
  90 ::
  91
  92 ////////////////////////////////////////////////////////////////////////////////////////////////////
  93
  94 go to link::Tutorials/Mark_Polishook_tutorial/15_Groups::