Summary: Ultrasone has done a proper job when designing the PRO900s. Everything right from their exterior design to the sound quality is really top notch. The sound is quite bassy but it is not over powered like on some other headphones. The only two problems I came across in my listening tests were the slightly elevated upper midrange which caused some tracks to sound a bit too sibilant for my liking.
Pros: Amazing bass, Nicely detailed and laid back midrange, Very detailed sounding, The treble has just the right amount of sparkle, Incredible build quality, Spare set of pads and cable, Good sound stage for a closed set of headphones, Light weight, Wearing comfort, Not the most demanding high end headphones on the market in terms of amplification
Cons: The price, Perhaps too much bass for some, The cups have a tendency to resonate a bit too much, Slightly recessed midrange