I have a confession to make.
Yes, I've been bashing the HD650 here, and for good reason. They are far more flawed as a whole than most make them out to be.
However...
Lately the HD650 has been growing on me like mold on a month-old bread. Not because it's some magical flawless headphone that makes everything sound good, but precisely
because it is flawed, and
because it adds character to music where on other systems it is sorely lacking. In effect, on many recordings, it
undoes the mistakes made in the production and makes the recording sound more lifelike than it would on a more tonally neutral system.
Yes, it adds bass to every recording, even in places where there shouldn't be any. But, compared to so many other colorations that I've come across, this one is actually very pleasing. Material that is strident and metallic sounding on a neutral headphone still sounds strident and metallic on the HD650, but it now has a weight and richness that makes it much more listenable.
I'm also very impressed by the resolution. The HD650 is not the most detailed headphone I've ever heard, but it manages to be fairly detailed despite not having any sort of pronounced treble or upper midrange spikes. If you take a lot of dynamic headphones that you'd consider detailed and EQ down their treble and upper midrange until their FR matches the HD650, you'd be surprised how much more detailed the HD650 is.
My main issues are still the slowness and the overall lack of dynamic punch. It's not that the 650 lacks slam, or even raw dynamic range... it lacks
punch, which is the subjective sum total of the dynamic aspects of its presentation. Whatever it is, it's not there.
I think the presentation is just too laid-back for me.
Still, having listened to it for a few days straight, I'm impressed. I'm glad I decided to hold onto my pair (well, it's no longer mine strictly speaking, but that was how I managed to hold onto it
).