"Arny Krueger" wrote in message
. ..
"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.

Agreed. They must be better than nothing, but probably have
little bearing on what might be happening in a complex musical
signal.

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.

There seem to be several opinions regarding the
frequencies of the fundamentals used in such tests.
Is there any standard?
I have seen 70Hz and 6kHz mentioned, and
also 19kHz and 20kHz.

Swept 2-tone tests are more to the point.

Much more like music.

Multitone-based tests can also work well.

Multitone is indeed interesting:-)
Are there any recommendation for centre frequencies?

Iain