Also, regarding the sibilance (S sounds). If it's in the recording and de-essing is not done properly (or artist made a decision to have hot sibilance on vocals for some reason, for example), then you have to hear it in the headphones, as otherwise it would mean that your headphones are too far away from the intended (or unintended through inexperience etc.) sound source, and basically are not very good. ATH-M50 will show that to you. If the sibilance is in the recording, you will hear it (but not excessively), while with the DT990, D2000 or UItrasones the sibilance is in the core of every song and every recording, IMO. That's the difference between the headphones and monitors - it's not enough to make headphones linear (as some manufacturers claim), because, unlike when listening to monitors or speakers, where the sibilance dissipates while sound waves travel through the air, get absorbed by walls and all kinds of materials etc., the distance between the listener and the sound source is non-existent while listening to music with headphones, and in the above mentioned models these piercing high frequency sounds are not dampened at all, it seems, which means a painful listening experience where you get ear fatigue very quickly. I have not noticed this trait with ATH-M50 whatsoever.