Interesting you'd post that. I have quite an array of headphones and I've been finding HE-400's darkness to be ideal for classical. One question: Are you using velour or pleather pads? If you're using the pleather, order some velours ASAP. It's a world of difference like you wouldn't believe.
Most audiophiles feel bright=classical for some reason, and for the life of me I'll never understand why. Anyone who's spent any time in the concert hall knows the sound of real seating in a real hall, especially up in the balconies (i.e. the most expesnive seats), is DARK. The whole building is padded and carpeted and wood finished for exactly that reason, to make it dark and lush. To me, HE-400 running on a hybrid tube amp sounds very much like the tonality a real concert hall has.
You will not hear all the breathing of the players, the complete string sound and the air between instruments with them. You will also not hear those things in the concert hall presuming you're not standing at the conductor's podium. If you are standing at the conductor's podium, then take your six-figure-salary-making 1st class flying rear end and go buy some Stax SR009's and be done with itI will never understand the audiphile obsession with bright headphones for classical that sound nothing at all like sitting for a live performance sounds. As a big classical buff I can say HE-400 and some nice warm tubes and the velour pads is as close to an authentic concert as your listening chair might sound.
Caveat: I'm also building an HE-6 rig at present which is indeed supposed to be more balanced, more detailed, and a bit brighter, but I'm counting on the overall HiFiMan real-life tonality to continue to be present with a different tonal balance. It's a departure from HE-400's darkness, certainly. But it also won't be my every-day listening headphone but for something special and perhaps "better than real life"
Note that all this is my opinion and for some reason lots of audiophiles do like really bright headphones for classical, And "better than life" can be a treat which is why I'm building my HE-6 system. But HE-400 does have a remarkable lifelike feel to the real hall, IMHO. Personally I prefer it for classical over HD650, D5000, K702, while preferring the others for rock and the like. I'm split between HD650 and HE-400 for jazz, 50% of the time for each.
