However, I was a bit shocked because the DT990 sounds with many things that I like to listen to very "hectic" because he can dense soundscapes dissolve not very good. Since he can not hold a candle to the HD545, which sounds very analytical and typical of Sennheiser even densest compositions nicely graded that one can imagine run over at any time. Then, however, the great moment of the DT990 strikes recorded in "flat" not very dense material (no matter what genre), where he just makes a lot more capricious. The bass is there quite bulky (my ears hair tickling as a bit) and the sharp "spikes" heights you get used to and seems to largely disappear during the import.
Thus, my conclusion is that the DT990 is not really suitable as a "single headphone", but appears as a complement to a "serious" model as created. I now have a couple of hours through part of my collection and discovered some new songs, my ears buzzing now something -. So I like that :-)