Did I say that the FR for headphones should be flat? I'm sure the Denon AH-D7100 is very mellow. The are visually very attractive.
Well, the Sennheiser HD 600 costs $400 at HeadRoom, whereas the Denon AH-D7100 costs $1200. Hmmm . . .
My own primary headphones, the Sennheiser HD 598, which were the most beautiful headphones I had ever seen, cost $250 and measure far better than the Denon AH-D7100. They are certainly comfortable and very easy to listen to.
Sennheiser HD598
The Sennheiser HD 280Pro is quite a nice closed headphone for $100 used by a lot of pros, apparently. They are quite good, very clear on voices. They can be unforgiving of some recordings. They apparently can take a lot of abuse.
Sennheiser HD 280 Pro - Full Size Headphones | HeadRoom Audio