Compute total harmonic distorsion of a signal:
  • Close to zero means purely sine
  • Greater than 1 means many harmonics
Note: For more details about this macro, consult this additional document


  • Select extrapolated curve
  • Select corresponding spectrum curve


  • Display the result of the following formula:

    T D H = a b s ( 1 s t _ H a r m o n i c 2 - r m s _ V a l u e 2 ) r m s _ V a l u e

  • And create an I/O parameter called DISTORSION