unction is used to synthesize spectrum. CubicPadSynth
  uses normal distribution curve for profile, which is same as original
  PADsynth algorithm. Center frequency of profile can be set arbitrary.
  In default, CubicPadSynth uses fundamental frequency set by
  <code>Base Freq.</code> and its overtones.</p>
  <p><img src="img/padsynth.svg" /></p>
  <ul>
  <li><a
  href="https://zynaddsubfx.sourceforge.io/doc/PADsynth/PADsynth.htm">PADsynth
  algorithm</a></li>
  </ul>
  <h2 id="block-diagram"><a href="#bloc