That, I don't know, but it's probably a moot point as...
... this is where there could be a more or less moderate problem. If we were to carefully equalise two different headphones to the exact same target on one specific dummy head rig, they would measure differently (at least a little bit) on another dummy head rig.
Even more importantly, if we were to measure only one pair of headphones on real humans near the drum with probe microphones (https://www.etymotic.com/auditory-research/microphones/er-7c.html), the exact same pair of headphones would measure differently, and in a way that's highly unlikely to vary according to each human's natural HRTF (https://en.wikipedia.org/wiki/Head-related_transfer_function), so TLDR not in a beneficial way.
That study is behind a paywall but illustrates these variations across six listeners and compare them with dummy head measurements :
https://www.aes.org/e-lib/browse.cfm?elib=16877
What I like quite a bit about it is that quite a bit more care was taken to precisely position the probe tube than in other studies of its kind I've seen.
The variations are the most extremes at both ends of the scale. At lower frequencies mainly because of sealing variations and past 1khz because of the individual's ear anatomy. In the 1-5khz range they're moderate (a few dB), past 5khz or so they're not.
Since the variation between the six test subjects is highly inconsistent from headphones to headphones (six tested), then it's logical to conclude that the tested headphones don't interact with our ear's anatomy in a natural way, similar to, for example, speakers (if so we'd see the same variation across the six different headphones for the same listener).
Now this is just me, and probably wrong in some way, but the way I personally interpret such a study, beyond the obvious "don't over-interpret dummy head measurements past 5khz or so" for example, is that :
- these variations largely exceed threshold of audibility in parts of the FR spectrum. Since these variations necessarily are, at least to a degree, undesirable (not matching the way our anatomy induces variations with speakers / natural sound sources), they could explain the differences people hear between headphones, even when equalised to the same target on a dummy head.
- but these variations tend to be, at least below 5khz or so, lower than the variations we see across headphones in general.
So it lends credence to the idea that we can know one thing or two about what a desirable target curve should be, but that once we're close to it it's difficult to know which headphones will suit someone better than another.
And we haven't touched other subjects such as measurements methodology variation, sample variation, positional variations, pad wear, etc...
TLDR : if equalised to Harman's target according to a third party measurement and preset, the likelihood that the HE-1 and 009 will actually have the same FR curve at your own eardrum is next to zero, and it's highly likely that the difference will be above threshold of audibility (but probably less so than without any attempt to match their FR curve in the first place, as at least one of them deviated quite a bit from it).
If you want to see my own limited experience of these issues at least below 1khz (I have no reliable way to know what happens above, and even below take my own experiment with a pinch of salt) between a HD560S and a HD650 on my own head, equalised to Harman : https://www.head-fi.org/threads/the...-at-a-breakthrough-value.943107/post-16300055
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