Pros: Superb sound-stage, amazing lows, crisp highs, comfortable for extended listening sessions, aesthetically pleasing.
Cons: Design and materials could be better. A metal reinforced headband would have been preferable. The amp you use can make all the difference in the world
I have only had these headphones for a little over a month at the time of me writing this review. I choose to write the review now because I feel confident in my ability to properly asses these headphones from an objective point of view with minimal bias. This review was written at work over the course of a shift, it is by no means well layed out.
First off....These headphones are understandably flat and dull when used without an amp, anyone expecting auditory greatness (Over the Ear) from a 3.5mm jack running off of your phone is insane.
What I listened to on my HD650s: Classical, Rap, Rock, Classic Rock, Metal, Death Metal, Melodic Death Metal, Symphonic Death Metal, Alt Rock, Dubstep, Trance, Jazz, Techno, Pop, Progressive Rock, Progressive Metal. Television shows, Movies, PC games, Skype conversations.
Quality of source material: Primarily 16-bit 44KHz ALAC, Vinyl, 24-bit 96KHz FLAC
What powered my HD650s: Tested on 2 amps at home in addition to my portable amp solution Fiio e17
Use: 6-8 Hours a day for a little over a month at home in chair/bed, walking, and even in my car.
Experience: Easily the best headphones I have ever owned. The bass response is superb and will lull your ears into nirvana. The highs are crisp and distinct but never feel like they are stabbing your ear canal. I decided to test MP3s with the HD650 and was astonished at how 320Kbps tracks were sounding through these cans. No where near perfect, but damned impressive for the source material. I listened to music the most sitting in my lazy boy chair at my computer or laying in bed. I have actually fallen asleep listening to these headphones, they are really comfortable.
Conclusion: This review was kind of sloppy, but I can easily recommend these cans to anyone looking for a delicious audio experience. AMP MAKES ALL THE DIFFERENCE
The 2 amps I used are nowhere near audiophile quality, but they provide enough power for these cans through the 1/4 inch jack and they sound really nice to my ears.
What I really meant by AMP MAKES ALL THE DIFFERENCE was that these headphones really need to be powered by an amplifier to sound good and will sound very flat if they are just using a standard 3.5mm jack from a computer or phone.
Hope I made some sense with that.