It does seem strange that the bass levels are different, as you'd think bass measurements would be least affected by different choice of ear design, but of course it's obvious that the same target curve can't be used between the two measurement rigs (which is what's been done in this slide, but I don't think you're referring to that point specifically). I caught a snippet of your earlier posts where you postulated that seal might be compromised on the less uniform sealing surface of the B&K 5128 vs the flat surface of the GRAS 45CA - seems likely however the swivel mechanism of the cups on the K702/701 are very flexible and can move freely in all dimensions to allow for optimal angular contact with the surface, but it's still easier to imagine a better seal being achieved on the GRAS 45CA. Perhaps size/depth of outer ear makes a difference if they are different in spec - for instance it seems the closer the driver is to the outer ear then the more bass you get, as seen in worn pad vs fresh pad K702 measurements where thinner pads = more response below 1kHz (or less treble depending on how you look at it)......so perhaps if the B&K outer ear protrudes less from the head ("less deep") then therefore the outer ear is further away from the driver and therefore perhaps less bass, just an idea.As I appended to my last message above to metal571, I think that would probably depend on the time frame between the measurements, and whether they were done with the same pair of headphones.
I'm guessin that Harman probably made the two measurements shown below using the same pair of AKG K701's though. Probably over a fairly short space of time. If that is the case, then different amounts of wear, or the other issues related to revisions or manufacturing that metal571 touched on above would probably not be the issue in this particular case... Probably.
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