Who already have a HD600 and DT911, DT931 what surprised me when I had the ears the first time in the store.
Listening is not really neutral, there seems to be a hole in the medium. The sound of the subwoofer down the middle of the meduim of a very regular basis, then up to the high end very slowly too. This gives a perfect readability of low to high, a very fat, even a little cold or some cd with some headphone jacks. Almost all classical music goes very well on the pop-rock, disco, and French music, its superiority is less evident. In fact, his forte is in a good definition, good dynamic, and above all a superb stereo, almost 3D. We perceive the different acoustic room (standard or live) very clearly, like the high-end stereo systems.
This headphone is hard to find second-hand but you can find these impressions of what a replacement version of the DT990 hifi, not safe for the pro version.
A little gem that always brings so much pleasure.