I guess this is kind of an early mini-review, so here goes.
Okay, so it's been a week; a week of listening, break-in, and comparison. What I can say at this point is, I don't love the HE-6. I like them, I appreciate their sound quality, and they do compare well with the Senn HD800s, but they're missing something.
See, we like people for their virtues. Their positive traits often inspire us and we find that that inspiration can often make us want to become better people ourselves. However, we love people because of their flaws and imperfections. We come to appreciate those idiosyncrasies and they help to remind us that imperfection is part of what it is to be truly human. If you lived with a perfect spouse you'd get bored out of your mind before long, there wouldn't be any "zing", no chaos to allow for partnership chemistry to work.
That's the deal with the HE-6 too, as well as the HD800s for that matter. The flat FR graphs, showing a tonally perfect pitch, are evidence of a high precision tool for measuring audible variables in well-mastered sound recordings. However, for listening to music, trying to enjoy it, they're about as dry as week old toast. It's like using baking soda to brush your teeth. It does the best job, but the flavor leaves a lot to be desired. When I reach for a set of cans for relaxation and enjoyment, I grab my D7000s. They're flawed, imperfect, and sometimes annoying, but I love them. They relay passion and energy with no apologies, they're agony and ecstasy with very comfortable pads. That's the D7000 in a nutshell. The HE-6 has no art in its presentation, and for many that's exactly what a headphone should do, be neutral, passionless, and only deliver what it takes in. That's fine, I can get behind that, but it isn't what I want every time I listen to my favorite recordings. I can never love them, but as I said before, I do like and appreciate them, they do what they were designed to do, and that's essentially what I wanted.
Then, I go to the presets I made in my parametric EQ...
See, the great thing about really high quality neutral cans is that they are truly kick-ass chameleons. "Hmm... do I want to dial in a pair of LCD-2s? Yes, I think I will." "HE-500s? HE-400s? No problem." Do I feel like some Grado action? Pull up the mids, drop some bass and highs, and suddenly Joe Satriani is in the house. There's no drama, they just handle it. Want even more flavor? I plug in to my EF-5 with a Mullard 10M and crank it. It's like putting the gorgeous, but sometimes boring, Jessica Alba in a pair of leather chaps and giving her a bull whip (gotta love Sin City).
Thing is, with little work, and perhaps some tubes, HE-6s can be whatever you want in a headphone. The clinical perfectionist becomes a party animal, and that I love. Now I just need a great tube amp with balanced output.