Sorry "to burst your wish" again
, but even if that was true, HD are only one of the loudspeaker distortions.
More problematic and audible is IMD and there exist even harder to measure non-linearities like decay problems, port noises, enclosure vibrations which can make the difference between a good and an excellent loudspeaker.
Here for example the IMD/multitone distortion of two very good loudspeakers with inaudibly low harmonic distortions above the bass:
View attachment 95260
Source:
https://en-de.neumann.com/product_files/7950/download
I own myself a pair of 2-way KH120 which at the normal listening levels have above the bass according to the graphs inaudibly low HD, but again as also other posters have written their sound quality doesn't reach the one of the 3-way KH310.
Although you don't want to believe till now
, there is a reason that all 4 posters who have listened to both the JBL and Neumann in the other thread said the loudspeakers sound quality isn't comparable.
Excellent, so do I, we are here all to learn and share our experiences and knowledge.
1M sounds good but also please do it in the direct nearfield like 20cm and only with one loudspeaker, so only the uncertainty of your measuring chains remains.