How do they sound in comparison to the HE-400 and HE-500 ?
Caveat: All listening was done via the Hifiman EF5 and the 901 DAP. There was an Emotiva CD player there but they refused to hook it up because they said it sounded so bad, it was only there for show I was told. The EF5 is a colored amp w/ some headphones and might have interesting synergy issues. IME, it tends to be tuned w/ Fang's headphones in mind, so keep that in consideration w/ impressions from it.
The 400i seems to have fixed the weird midrange distortion that some are able to pickup. They do sound better, more coherent overall signature and better clarity. Still less smooth and refined than the other Hifiman phones further up the range.
560 sounds quite a bit like the name implies a 500 adding a bit of 6 treble in the signature to brighten and open it up. Less warm than the HE500 with better clarity. Whether there are serious sibilance or treble issues is hard to tell as I have found in the past the EF5 to take the edge of such artifacts at times.
Overall, the HE6 had less of that full fleshed out bass compared to the 560, but every other technical metric apart from FR like speed, smoothness, refinement, imaging, were all superior on the HE6 still.
I'm afraid that's the best I could do under the time constraints and gear under show conditions. I spent more time w/ the 901 and 802 as I felt DAPs, DACs, DAC/Amps were the rage this year. I'll have more on that in the CES thread.
