Three distortion methods, the harmonic, the SMPE intermodulation, and the CCIF (a difference frequency), have been studied, mainly on a theoretical basis, as a means of analyzing distortion encountered in phonograph reproduction. The harmonic method is somewhat difficult to apply and some of the harmonics may be beyond the range of the system. The IM has been used in the past with considerable success, and appears to be a good method of analyzing tracing distortion. The difference frequency methods appears to be somewhat insensitive to tracing distortion but offers theoretical advantages in that the analysis may be made right up to the cut‐off frequency of the system, practically it is somewhat difficult to apply.