P Cut Offset [st.]</dt>
  <dd>
  <p>The value added to filter cutoff frequency, which is calculated
  from <code>Cutoff</code> and <code>Cutoff Slope</code>.</p>
  <p>On the control, the order of harmonics becomes lower towards left,
  and higher towards right. Note that higher harmonics may affects lower
  frequency, and lower harmonics may affects higher frequency. This is
  due to the cross feedback on FDN.</p>
  </dd>
  <dt>LP/HP Q Offset</dt>
  <dd>
  <p>The value added to filter Q, which is calculated