= Cutoff * 128
keyFollowRange = Cutoff * (nTable - pitch)
lowpassPitch = (cut + KeyFollow * (keyFollowRange - cut)) - lowpassEnvelope * Amount;
if (lowpassPitch &lt; 0) lowpassPitch = 0

noteToFreq(note) := 440 * Math.pow(2, (note - 69) / 12)
range  = noteToFreq(nTable)
lpFreq = noteToFreq(midiNote + lowpassPitch)
ntFreq = noteToFreq(midiNote)
cutoffFrequency = (1 + (range - lpFreq) / range) * ntFreq</code></pre>
  <p>128 used to calculate <code>lpCut</code> is an arbitrary value
  which came from MIDI note