For people without experience with both the HD800/HE6... Don't get confused with what's being said; the HE6 has much more presence in the bass regions in comparison to the HD800. It's very significant. As for bass quality; that's a toss up, but again, probably the HE6.
Having owned the LCD3/HE6/HD800 all at once for a long time, I'd rank the bass as such:
Bass quality (resolution/extension)
Bass quantity (slam/visceralness)
IME the main difference between the HE6's and HD800's in the bass department is the bass is fuller on the HE6's and only slightly deeper.
Don't really notice more presence.
The bass on both is impactful, very fast and very tight with the HD800's at least giving the impression that it is slightly tighter but that could be because it's leaner in the bass but never lacking (assuming a good source/amp and decent recording)
Edited by nigeljames - 6/24/13 at 3:01am