You hav very interesting FR graphs. I can see that the T1 is not for me, The Senn HD6XX goes wonky after 3K. I wonder what that is about? Mark that one off my list. The Grados have a low end shelf of up to 5 Db. Not good for sub-bass. I see the DT880s have an actual boost of 5 Db at 8K, not 3 Db. Yes, that would definitely bother some ears. It would not and does not not bother me due to my hearing peculiarities mentioned earlier. I think older people do need the HF boosted anyway. I wonder if it is possible to map the FR when the headphones are being used with a particular amp?
As a note, the FR graph of the DT880s is different from the one published by Inner Fidelity. For instance, the graph from Inner Fidelity shows much more recessed mids, also where the highs actually show up with less of a boost, I think yours is more accurate. What are you doing differently?
I wonder what the Amiron Home headset FR would be? This is my next purchase as a goal of mine.
I have both the Amiron Home and a T1.2 Black, the Amiron has a more noticeable spike than the T1.2. The FR response doesn’t tell the whole story of the T1.2, Amiron Home, and DT 880 compared to each other. The DT 880 600 I personally found the leanest and brightest of those three. The most akin to the DT 880 of the Tesla Beyers I heard is probably the DT 1990 Pro with analytical pads.