I'll repost it because it's a shame if it'll be lost.
Well, thank you for that. Maybe it's not worthless ... I don't know at this point.
Let's put it this way:
If two speakers sound different, they don't measure the same.
If two speakers measure the same, then they don't sound different.
Let's start with two different speakers, each having perfectly flat on-axis response. Specifically the ways in which they might
not measure the same according to a basic suite of tests include:
1)
total radiation pattern - frequency response differences between on-axis and off-axis. This includes differences in the distribution of bass energy.
2) distribution of nulls - reflected sound having a different timbre one from the other due to, among other things, differences in interdriver spacing.
3) individual drivers exhibiting differences in distortion, especially at different frequencies one from the other.
4) resonances. I firmly believe that this is a big one.
5) radiation pattern of individual drivers - even slight differences in dispersion (beaming) can cause detectable differences in off-axis frequency balance even though on-axis frequency response is identical.
6) if the system is ported, then the port can contribute differences that are subtle, but unwanted.
7) enclosure diffraction.
8)
total distortion characteristics of the two speakers. I believe a slight difference in distribution of distortion is a vastly underrated factor in listener acceptance.
Detecting these small differences demands a suite of measurements for which the degree of precision is impractical (or too expensive) for most testers. It would
not be a "basic" suite of tests.
These differences may be both audible and measurable because although the human hearing system is poor at determining
absolute values, it is very good at determining
relative values, as in relative differences.
One more point: we know that a loudspeaker cannot recreate the original soundfield of a live performance. Therefore, you might like to think of these characteristics as imperfections within a larger imperfection .... and you would be correct. That's no reason to abandon the fight to improve the state of audio reproduction as a whole. Edison's cylinder (1877) was only less than 150 years ago. I think we've come a long way since then.