But what if the scoring is done based on measurements like Rtings and Oratory1990 ?
For Crinacle it is another matter.
A reason why I do not rate headphones at all.
Measurements only say so much and people evaluating things are biased.
Rtings needed something to rate soundstage. A number produced by measurements. The HD800(S) has some of the best 'soundstage' and thus they looked in the frequency response for 'something' that has to do with pinna related effects and as they liked the HD800 (they didn't measure many headphones back then) they thought that response thus must be related to the measurement of the HD800.
That FR thus was taken as a reference for soundstage.
However, if that really were the most important aspect then simply lowering those specific bands in any headphone would increase soundstage.
It doesn't but became their 'reference'.
That dip also is angle and driver size/distance dependent and your and my ear may have it at a different frequency.
Those rigs dip around 10kHz and thus mask a peak when it is there. The weird thing is that when I sweep at those frequencies I never hear a dip there. Reason... Our ears may well 'dip' there but our brain knows this and knows it is direction dependent as well. (my theory based on my observations about sweeps and measurements)
Could also be that the frequency bands of our haircells are too wide and overlapping have something to do with not perceiving a dip where the microphone and analyzer do not work this way. That's why smoothing was invented. It often has a higher relation to perceived sound. certainly for dips.
I have no experience with headphones, but in speaker/driver design, when you go for the top end of what can be done, you end up looking into the pistonic properties of driver diaphragms.
You can make drivers have a wide range for a speaker- s(ay 60hz to 2500hz) but when your requirements are too wide of a band, you end up having to go in one of 2 directions- either you have a compliant material, where it no longer acts as a piston for most of its range, but the modal breakup is 'soft' and wide Q. The ear seams less sensitive to this, and you can also use passive filters to drop the peaks etc.
The problem with this is that you can only correct for it at one location in space and you have to choose where this is. However, with speakers, you still hear much of the sound that is projected into different directions, just delayed after the fundamental as its just post bouncing off a surface in the room.
I can't say how this effect works inside a headphone casing, but I would 'guess' over earphones would be wave propagation and reflection affected by it in some way...Audibility at this distance of reflection, no idea.
The HD800s has what transducer designers call a ring radiator driver. The advantage of these is holding pistonic motion up to a relatively higher frequency.
In Speakers, the ultimate example would be the celestion Axi2050 or JBL 2430K
When working with a ring radiator, the designer has an improved ability to use a hard material, pushing the break up of the cone to higher frequencies where our hearing is less sensitive, or use cheaper materials in a more pistonic fashion. The Sennheisers opt for the latter is seems. I know AKG are using titanium, I wonder if they are Aquaplas coating the diaphragm or going raw?
Anyway, the ultimate option would be either a diaphragm made from uber expensive Berylium, or new materials like carbon based TExtreme. I am not aware of anyone using these in headphones, and would be surprised if Sennheiser had not been in contact with Materion to try this out, but then I'm new to the game!