Comparison-wise, the highlight had to be my session switching between my HE1000s and Mark's HD800, on his McIntosh system.
What I thought:
- HD800 had a more growl-y, "audibly textured" bass, while HE1000's bass was more tactile and "physically textured". Both were exquisite, but in very different ways. Based on quite a few tracks, I found HE1000's bass presentation to be more musical and fun, without losing out on the low frequency detail level.
- Mids-wise, both were close to neutral but with slight colourations; HE1K comparatively was warmer but more laid-back, while HD800 cooler and more forward sounding. Detail-wise both have zero complaints from me, at least at a meet background noise setting.
- Treble. My brain felt that HE1K had the better treble tone, but HD800 had the better treble technicalities. Both are very close to optimal treble tone AND technicalities though, but swapping between them I noted this dichotomy.
- Headstaging / 3D imaging...both headphones are able to achieve "out of the head" lateral headstaging. HD800 does it a bit more cleanly, but HE1K presents a much more dramatic and impress-able headstage because of the sheer physicality of its sound.
But ultimately, the crux of HD800, as I have found time and time before when auditioning it on different systems, is that it is just not a genre master. It is a savant at some genres, excellent at some others, and just not that enjoyable for some genres. Meanwhile the HE1Ks held an impressive constancy in terms of how much they make every track (regardless of genre) FUN, despite it being a neutral, flagship-esque sound signature and characteristics.
That is really something not very quantifiable, it is the overall cohesive experience. Listening to HE1K side-by-side with HD800s yesterday, I realized that HE1Ks' real strength is actually that.