"John Phillips" wrote
in message

I have sometimes pondered (without real cause, I admit)
about whether the "usual" IMD tests are good enough as a
predictor of audible IMD effects.

Not really.

Do you think the normal two-tone IMD tests (from SMPTE,
DIN, IEC, etc.) provide an adequate basis for testing something
where (I postulate) more complex IMDs may be the more
audible effect?

Not really.

Swept 2-tone tests are more to the point.

Multitone-based tests can also work well. Do it right and you can get a
good fast FR test and a good test for nonlinear distortion at all audible
frequencies done with one test, two analyses.