Got them yesterday. When I just put them on the first thing i noticed was how different the sound signature is from my beloved Triple.Fis. Mid bass was too powerful , so I had to EQ them a bit in that area. After about 2~3 hours of burn in, I decided to test them with my Motorola Atrix CM7.1 Interestingly, Atrix has no problems with loudness, it runs XB500 just fine. At about 75% volume levels get uncomfortably loud, which is surprising ,considering the fact that XB500s have pretty large speakers inside them. The music I played was the following: RHCP (last two albums), Muse, Sepultura(latest two albums), Dream Theater (2011 album) and some good old Gravity Kills! To my genuine surprise, XB500 played really well Sepultura's complex and fast music. I can say that in terms of speed and detail XB500 are comparable to triple.fis ! Of course sound signature and the body of the low end is spectacular on triple.fis but the rest is pretty comparable. To be honest , I expected XB500 to have slow and muddy bass, but my expectations turned out to be false. As for the other music, XB500 played them reasonably well ,especially Gravity Kills with it's heavy bass! With Muse, I noticed that the headphones have pretty clear and vivid midrange (after EQing of course) , which is something that does not exist in sub XXX$ bass headphones. Comfort wise, these headphones are just ridiculously comfortable, in that area they are on par with Bose headphones. Which raises a question: why on earth would anyone pay 3x~4x price for Bose headphones which have miserable sound quality when compared to XB500 ?
On the negative side I found highs a bit harsh and not as transparent as on triple fis. Instrument separation is also not as good. The overall impression is lack of transparency and lightness. Bass on triple.fis carries much more control and momentum. XB500s bass is not as good. But is it fair to compare to triple.fis?
The reason I got Xb500 is because cable on my triple.fis broke after one month of use of that cable. I called Logitech and they said they will send new one after 7-10 working days (I really doubt they will)... So I decided to get temporary headphones.
For 44$ that I paid I would reccomend these to anyone in a heartbeat. From my experience XB500 are far more interesting than ES7 or AKG Closed and Portable K series. Something is telling me that they might even be better than HD 25 I. Can anyone comment on that?