Hi, I need comments to my narrowed down selection below, in preference order: 1. Beyer Dynamic DT 770 PRO, 80 ohm 2. Audio Technica ATH-M50 3. Sony MDR 7506 I've chosen fully closed ones, as I work off my appartment with people sometimes bumping a bit upstairs and some traffic noise from the outdoors. I'll need to be able to partly mix with the headset, as obviously I won't always be able to work well enough with monitors. The ATH-M50 reportedly has very few artefacts, and is long-term comfi. The Sony is said to have a big button (often desirable by bass players and drummers) and maybe being almost too clear in the treble. The very comfortable (to my head) DT 770 PRO exibits 18 dB damping, the 'm' version, marketed for drummers, does 35dB. I haven't found a real good explanation to the sonic difference between the 80 and 250 ohm models. Likewise between DT-770 and the 'm' version, except that the m-version may have more of a 'big buttom'. I realize the 990 model is a decent improvement, but alas, it's not a closed type.