For anyone interested I upgraded from the Sennheiser HD660s to the HD660s2 and was blown away. Got them for $400US on sale after Christmas, and they're paired with a Schiit Asgard3 headphone amp (with the cheaper DAC, not the "multibit") and Amazon HD is the source.
I'm a bassaholic and upgraded primarily for that, which is indeed improved but still nowhere near what I like (I boost bass with EQ APO). However, the improvement that blew me away was the imaging. The best way to describe the difference is watching the performance from a distance (660s) vs. being fully immersed in it (660s2). The midrange & treble is far more "present", though not harsh (I'm sensitive to midrange). More "texture" is another description that comes to mind. I was astounded to isolate a quiet backing vocal at a pinpoint location and perceive they were mumbling rather than annunciating!
These headphones have been nothing short of a revelation for me. Used to think headphone listening was far inferior to the amp/speaker experience, but that's now changing!
I'm a bassaholic and upgraded primarily for that, which is indeed improved but still nowhere near what I like (I boost bass with EQ APO). However, the improvement that blew me away was the imaging. The best way to describe the difference is watching the performance from a distance (660s) vs. being fully immersed in it (660s2). The midrange & treble is far more "present", though not harsh (I'm sensitive to midrange). More "texture" is another description that comes to mind. I was astounded to isolate a quiet backing vocal at a pinpoint location and perceive they were mumbling rather than annunciating!
These headphones have been nothing short of a revelation for me. Used to think headphone listening was far inferior to the amp/speaker experience, but that's now changing!