Here are the 5128 measurements for those looking for those along with a visualization of HPTF variation. Graphs with comparisons to the original HP2 will get posted today!
https://forum.headphones.com/t/hedd-audio-heddphone-two-gt-official-thread/24272/8
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The pads are nearly identical - Purple is leather, orange is suede.
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HpTF Variation (2 heads):
Leather
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Suede
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Not sure what this is?
Headphones behave differently on different heads. Everything from pad deformation, to the size and shape of the physical ear filling the space, to the way it sits on the head can all have an influence on the frequency response at the eardrum. If you’ve ever seen a graph and thought “but this doesn’t match my experience”, HpTF variation (headphone transfer function) is likely the reason why. And yes… this is also one of the key factors in explaining differences in perceived ‘technicalities’ among listeners, but that deserves its own separate topic.
So far we’re showing just two ‘heads’ with their own unique pinnae, in the form of the GRAS 43AG’s KB5000 and the B&K 5128’s pinna, but ideally we end up developing more to test on in the future."
As a note, the pads being nearly identical is what HEDD was trying to achieve as they didn't want those that did not want leather to have a different sonic experience. So it's good to see that Dmitry was able to achieve that!