Harry Houdini wrote:
David,

Dynamic distortion - something I've been thinking about recently
too.
Too bad this specification doesn't make the A-list in most
manufacturer literature.

AFAIK, dynamic distortion has no formal definition.

TIM & SID have been studied to death and found to be the same as high
frequency nonlinear distortion.

Probably the best way to measure high frequency nonlinear distortion
is a high frequency twin tone test, such as equal parts of 18 & 20
KHz sine waves. Analyze the output with a spectrum analyzer. Look at
the sidebands that are generated, if any.