NOTE: PLEASE READ!! This is an update to the review posted below.
I owned the KRK KNS-8400 for over 6 months. Eventually I found myself not needing an extra closed portable headphone so I sold it. I always liked it, so I decided to give it another try in July 2011. I should have kept it!
The pair I received in had NONE of that painful treble. It was a lot smoother and did NOT even remotely feel like icicles stabbing me in the ears. The bass was also quite good, but MY pair still lacked in bass impact. The mids sounded the same, but it's signature felt a tad more natural. I have absolutely no clue why or how, but the soundstage felt a lot better. I don't think I had a lemon, but most likely was just some strange variation between pairs. Mine was a very early pair. Overall I prefer the KNS-6400 for my music preferences.
You can find a review and some comparisons to the 8400 here:
The other day I saw these in stock at my local Guitar Center and I needed some new headphones that might sound like the Shure SRH-840 but were more comfortable, cheaper and much smaller. These looked like they might fit that description. I have my favorite DJ100, but that requires an amp at all times. I wanted an un-amped portable headphone that was not very large, but still sounded like a $150-$200 headphone.
The comfort on these is quite impressive. The most comfortable headphones ever to me is a tie between the k240 Studio and the Denon D2000. The k240 Studio might be the winner due to zero clamping force and how light it is. I love the D2000 pads though, but the headphone isn't that light. I also find the Maxell DHP-II extremely comfortable.
COMFORT, ISOLATION, BUILD QUALITY
These headphones have two bumps on the headband that are memory foam. You press on them and it takes awhile to come back to it's original shape. You cannot feel the headband against your head at all. The earpads are memory foam I guess, but they feel like the ones on my old Bose Triports (don't ask!) and my DHP-II. The comfort overall on these headphones is impressive. M50, SRH-840, DJ100, HFI-680 and similar headphones can't even come close. On my small head there is very little clamping force. Isolation is OK. Good, but probably not great. Comfort is a 9/10. My D2000 might have gotten a 10/10.
The build quality of the headphone is fine. I do have major issues with the cable. It feels and looks ultra cheap. It's as if they skimped on quality here. For a $150 headphone that's not acceptable. Have you ever gotten a headphone and the cable has that cheap rubbery feel? Think of the cable on the Creative Aurvana Live or k420 and it's just like those (but not as thin of course!). After a day it still retains part of the shape it was in when it was in the package. Part of it looks like it wants to stay in a square shape! It also seems to want to tangle. When I have the headphone on my head and I move the cable I can hear it a bit. Not when I play anything of course. The cable is removable and the volume control is a bonus and DOES NOT need to be attached!
The headphone is actually quite small. One of the smaller full sized headphones at least. They make the M50 and SRH-840 look massive in comparison. These would make a perfectly good portable headphone that sounds good straight out of an Ipod! They don't fold up, but the cups can lay flat. On my Ipod Touch 2G un-amped I need to put the volume 4 notches from the right to get enough volume. With my k240 Studio it has to be maxed.
I'm a huge believer of burn-in. I wasn't at first until I noticed some major differences with my k240 Studio, DJ100 and k601 after burn-in. I've found that many headphones really don't need burn-in, but some do. I usually like to listen to them on the first day and then burn them in when I'm sleeping.
This is a real Jekyll and Hyde headphone. My first day of listening to them was not a fun experience in any way (it gets better, trust me). The first thing I noticed is that the headphones were VERY fatiguing. They were excessively bright and I'm talking about like icicles stabbing me in the ears bright. This seemed to not always show up in some of my favorite music, but in other music it did.
At first I was thinking something like "maybe these songs are supposed to sound this way", but that's definitely not the case. I figured maybe the headphones would need to be amped and I used my Asgard. At first I thought it was a bit better, but not really after all. I didn't notice any differences between amped and un-amped other than volume increase. I didn't even have the volume that loud and when I took a break my ears were just ringing so badly.
Despite the piercing treble there was enough to like. The mids were very good. Vocals were crystal clear and easy to hear. Detail was almost at the point of being excessive. I think these are possibly one of the most revealing headphones I own. Imaging is very good and reminds me of how it was on the SRH-440. Soundstage is good for a closed headphone. I doubt a closed headphone could ever impress me with it's soundstage. The D2000 did almost. Out of the box this headphones signature reminds me of almost like the Shure SRH-440! A little brighter and less bass.
So far the weakest area of the KNS-8400 is it's bass. Even for a studio monitor/neutral headphone it doesn't quite have enough. I'm one who finds the amount of bass on the SRH-440 and SRH-840 perfectly acceptable. On this headphone there is maybe a tad less bass than on the SRH-440. The bass seems to have improved a little with burn-in, but I honestly don't know if it's my imagination...yet. As it is right now I'm OK with it's bass, but I just would have hoped for a little more. For comparison it does have way more than say the AD700.
At one point on day one I actually thought several different things. First it was that I wasted $150 on a sound signature I could possibly never get used to. Then at one point I said "I hate these things!". Another time I actually was thinking to myself that there was no way these were neutral and couldn't possibly have a balanced sound due to it's excessive treble. I was going to write a few impressions on day one, but that would have been a mistake and totally unfair. On day one the sound signature just felt a little too aggressive and did not sound natural in any way.
So on day two and with a little more burn-in they have improved by a LOT. The treble is now less of an issue and it's way less fatiguing in every way. No more of that piercing treble. A few songs give me issues, but they're like that on many of my other headphones, but not as bad as with day one on these headphones. On day two these are now much less fatiguing than say a Grado SR-80. Metal may be slightly fatiguing still with these headphones, but I don't listen to any of that. Fans of the Grado 325i and some Beyer Dynamic headphones would have probably had no issues on day one I bet! I may be really sensitive to treble and prefer slightly rolled off highs, but not too much. For me the treble of the DJ100 is PERFECT.
I've found these headphones to sound great for classical music for a closed headphone. It makes me want to listen to more classical music. Imogen Heap and non bass-heavy electronic music sounds great on these. For music that needs a lot of bass to sound good, this headphone is definitely a poor match unless it improves by a huge amount after more burn-in, but that's highly unlikely.
Right now on day two the sound quality seems "just right" and very balanced. Not too much of any one thing finally and just what I look for in a headphone. I've heard some of my favorite songs probably hundreds of hundreds of times and they sound no different on this headphone. The sound is very, very clear. Even possibly more so than my DJ100. Kind of like my old SRH-840.
For anyone that cares, these are way brighter than the SRH-840 for sure, but the SRH-840 has way more bass and it felt like the 840 had slightly forward mids. If I could find an SRH-840 with this design and with this level of comfort I'd be set.
I still feel it's a bit early to give them a final score for sound. I don't know for sure yet if the sound is better than the SRH-840 yet, but probably not. These are definitely going to be far better for some genres. In the overall view, these are better only due to better design, comfort and fit. The SRH-840 and the KNS-8400 would be a good comparison!
If you want a headphone to try and "Wow" you with it's sound, don't get these. They won't try and do that and that's what I look for in a headphone. Despite this they're not a boring headphone in any way and it's fun to listen to them. Basically I feel as if these won't try to change my music and make it sound better than it really is.
I can't say it enough, but this is another headphone that completely improves with burn-in. Even just a little helps. In total they've probably only gotten 12 hours of use. Tonight I've listened to them for three hours and my ears are not ringing and they're still comfortable. They have a totally non-fatiguing sound signature now. After day one this just made my day! I now really regret even listening to them before burn-in.
These cost $150 and overall they are keepers and worth my $150. The cable is just not good enough for a $150 headphone. KRK should seriously think of including a slightly better one. I'm so glad it's not coiled though! They could just skip the volume control and include a better cable instead.
I know some people probably think these headphones are ugly, but not me. I think they look pretty good. It's a good design, but they totally screwed up on the cable.
sound: 8.75 (not quite sure on this yet, sorry)
value: 8 (I'd add a .5 if the cable was better)
For comparison, here is how I rated my last few headphones (scale of 1 to 10):
Audio Technica ATH-M50 (black box version, white one sounds different)
comfort: 4 (too heavy and impossible to balance on small heads!)
value: 6 (if you can get them at $130 change that to a 9. Not worth $200 in ANY way. $160 max)
Koss Pro DJ 100 (amp required, should leave this off the list)
comfort: 7.5 (8.5 with M30 pads)
value: 10 (best $80 headphone ever)
Edited by tdockweiler - 8/3/11 at 12:45am