I am standing between Beyer DT660, DT770 Pro (80 Ohm or 32 Ohm) and ATH-M50 for portable use without amp. I listen mainly to classical music, less so to jazz and acoustic, rock, occasionaly to some electronic music. I need a headphone that seals good and is portable in the way that I can have it in my bag. It is important that it could be driven from an mobile device (an Android phone or iPod)
I have not heard any of these and would like to hear your opinions. From what I have read DT770 Pro is bass and treble heavy and mid shy. DT660 has great mids but is somewhat recessed in the bass range. ATH is more balanced than the Beyers but has lesser soundstage.
What is your opinion? Thanks!