Hi, it's for me a bit too soon to clearly say what they are capable of. I bought them few days ago and I can only play like less than 3 hours. Here are my findings, so far.
It's Linn Akurate CD player >> Lehmann Audio Linear >> DT1990Pro
The company around are K501, K712 Pro (Austrian) and DT770-250. There were others, including, briefly HD650.
First in a short demo at the shop: Violin tone and colour, fabulous. So I bought them straight away (I always buy the unit I was trying, no excuses).
Bring them to home and play Bruckner: dark, boomy but not too much, just after a short home demo of a new pair of HD650 they sounded somewhat similar. Yes, there was clarity, no sibilance or problems in the treble for me with that record (vinyl remaster on CD). Next day I changed to the A pads and they stay that way.
Tried again (same record, Karajan 1971 Bruckner 7 EMI remaster): no boomy, more taut bass, instead of HD650 bass-like, now is more K712Pro bass-like. I found it better for my records and my music. Maybe more clarity in mids, only maybe, and sharper treble but at the moment to issues.
But I noticed something weird: shouty, as in LOUD, in your face forward sound, not dynamic big swings, only a binary dynamic level: LOUD and low background music a bit far away. Loud and soft, separated spatially in distance a bit. And a narrow soundstage. It sounded really like a closed headphone with leaky closed soft cups (thin wood or similar). But I trust my ears and the tone colour, the timbre of the violin was there in the shop. And violin is something I struggle to get right on digital recordings.
So third day of tests: I bought Hahn/Salonen Sibelius Violin Concerto. I didn't know the quality of the record but I know the quality of the performers. Ok, good things and bad things. The good ones are the right ones: emotion, strength, holding my breath in two passages (really), music message passing through, feeling of intentions of the performers and the music is there. Gestures, tempi, articulation. Those things can't be 'restored' or 'repaired' by amps or cables. Or sources. But they can easily be destroyed by them. So far so good. Amp is a slightly cold neutral detailed SS device suitable for high impedance headphones. In the long past they were the default option from Sennheiser for their HD600-HD650 in their booth at HiFi shows. I'm not happy at all on how they drive any AKG and I think the pre-amp section is crap. But it works. Source is from Linn, 11 years with me and going strong. CD only device if you want to indulge yourself with a very good sound. If you try DVD-Audio or SACD in this device you will be disappointed.
But again the sound physical features I heard before are there: narrow soundstage, rumble in the bass passages, undefined fuzzy rumble, no definition (that was a bad surprise). Exactly like a closed headphone with no tight control of the resonances. Checked and rechecked the pads: firmly in place. And then again the two level dynamics: LOUD on your face upfront violinist, low volume, far away, hidden orchestra. Larger than life performer and an orchestra that appears mostly on the sides of the main performer like a pick-a-boo game, Snowwhite and the seven dwarfs. It can be the recording: there is a long modern tradition of closed miked soloist against an orchestra in the background, instead of mixing and balancing them together as it happens in the real performance on stage. But there are no reports or reviews on that account in this recording. I can test the record with the K712Pro and check what is in there.
I want to close my first report here with this: the nuances of Hahn playing, the emotion and tone of her violin and her own choices on how to play the Sibelius are clear. And there is no sibilance but the highs are close to be there, just a notch below, and you press your jaws in expectation of a pain that never happens.
I don't know if that Tesla 2 driver thing needs one hundred or more hours to develop. Please, if someone here listen to classical music, can you report your findings? Thank you.