The Klippel Distortion Analyzer can perform virtually  any type of distortion measurement. Single, double or multi tone, 3d  intermod, 3d harmonics, Hi-2 testing, amplitude compression, amplitude  modulation, etc. These tests can be performed with displacement  analysis to help troubleshoot the distortion cause. For example the  asymmetry of the compliance or motor can be measure and related to the  distortion byproduct.