Pros: Detailed, sparkly treble. Warm, engaging mids. Good sound stage and positioning.
Cons: Bass too boomy and not linear enough.
Comparison Review: ATH-A9X, ATH-A900X, AKG K550 Edition 2 I have decided to update this review, not only because I've spent some more time with both the K550 and the A900X, but because I found frequency response measurements for both of them on Golden Ears. I know not everyone likes the way they measure, but since there are no professional reviews of A900X other than on DigitalVersus, and since you shouldn't compare measurements taken by different websites/reviewers, I felt this was the best course of action to take. I have also updated/adjusted several observations in the sound quality section, a lot of which I feel is much more quantifiable now that I have reliable...(read more)