[sannee]

A more convenient value to measure is measuring the intermodulation distortion [1], since it does not require measuring harmonics that can be pretty far away from wherever the center frequency is.

It may be a bit of an overkill for audio, since I am not quite sure how consistently these systems usually perform across their entire bandwidth.

[1] https://en.wikipedia.org/wiki/Third-order_intercept_point#De...

[smoldesu]

Didn't know about that! I only come from a humble hobbyist audio standpoint.