[Mad Max]

Discussion died for the excellent KNS8400.
I'm liking the comfort a lot as the headphone is well-cushioned and very lightweight. Treble can be a little unpleasant on KNS8400 with stock earpads, but with HM5s, it becomes much more pleasant as well as natural. Isolation is decent.
The KRK's plastic also feels more like Sennheiser's to the touch, so I'm guessing that it should potentially be highly durable. I'm liking the overall sound better with HM5 earpads, but bass loses some definition and gains "one-note syndrome". Stock earpads render better bass, but also exacerbate the treble and reduce how natural acoustic instruments and vocals sound.
Music-wise, I feel that 8400 is a pretty good all-rounder. Classical music will sound better with HM5 earpads, otherwise, the headphone is nothing special with classical and stock earpads. It might even put off some folks versus something like DT660.

 

[kotomikun]

Funny that you would revive this thread now; the 8400 was my first, and still only, "good" headphone, and I'm finally (probably) getting around to upgrading.

I can't really compare its sound to anything else, since I don't have anything else that anyone around here would take seriously, but it's always seemed... good? I don't have an amp because I was told it wasn't necessary for them. They are certainly durable; after years of being dropped from desk height about once per day, they still work perfectly. Never had to replace the cable, though the earpads did eventually fall apart. Doesn't have any paint, which is nice, because my old Sennheisers basically turned into a paint-fleck dispenser after a while. My biggest complaint is the headband. Two tiny pieces of hard foam just doesn't work for me; somehow this is comfortable for some people, but I think most will need to add their own padding of some sort.

Weird that no one talks about these headphones anymore. Apparently they were a fad of some sort. Seemed highly recommended at the time I bought them.

 

[RobbaDobba]

I've owned the 8400's for a few years. My job got them as a replacement for the Sony 7506's and I liked them so much I bought a pair for myself. We just got a pair of the updated 8402's in-house, and I'm not sure I hear much of a difference between the 8400 or 8402's (which isn't a bad thing). I need more listening time, though.

Does anyone have any opinions on the 8402's vs the 8400's?