[Mooe]

They are power hungry; I'm not sure how well they would work without a dedicated amp.

Is 32Ohm powerhungry?

 

[zyzyx]

Is 32Ohm powerhungry?

The impedance and sensitivity readings for the KRK6400 are somewhat misleading, as is often the case with phones. The 6400 sounds relatively quiet for any given volume setting.

 

[Mooe]

The impedance and sensitivity readings for the KRK6400 are somewhat misleading, as is often the case with phones. The 6400 sounds relatively quiet for any given volume setting.

I see, so could you come to the conclusion that a headphone is power hungry based on how loud they can get?

 

[wilyodysseus]

I see, so could you come to the conclusion that a headphone is power hungry based on how loud they can get?

Well, "power hungry" certainly isn't a technical term, but that is what I meant in this case.

 

[sofastreamer]

one more question before pulling the trigger: how does the bass departement compare to that if the k701 or srh940?

 

[maestrochoy]

Quote:

one more question before pulling the trigger: how does the bass departement compare to that if the k701 or srh940?

I don't know the bass impact on the k701s and srh940s, but I felt that the bass impact was very minimal and almost non existent on the 6400s, but maybe it could've just been me. I switched to the 8400s, and they were there like it should have been. I'm not a bass freak, and I'm very sensitive to bass, but on the 6400s, I was trying to use cocktail party effect to pin point the bass, but I had to seriously listen for it. maybe I received a bad pair? but I'm very happy with my 8400s atm.
 
You should also consider just getting the 8400s because they're not much more expensive, better bass, a noticeable amount of improvement in detail, and superior comfort.
 
tdock's probably going to disagree with me though and say that the 6400s and 8400s have different sound signatures, 6400s has bass, and 8400s don't have that much more clarity, but like everything on this forum, it's what I heard and experienced so all opinions.

 

[sofastreamer]

i already ordered them and will give them a try tomorrow.
i thought the 8400 must look much more bulky because of the different headband construction? i want to use them outside.

 

[wilyodysseus]

They have identical headbands, and look equally nerdy.

I'm not normally a proponent of burn-in, but give the KRK's a day or two to settle down before you judge the sound quality.

 

[tdockweiler]

Quote:

I don't know the bass impact on the k701s and srh940s, but I felt that the bass impact was very minimal and almost non existent on the 6400s, but maybe it could've just been me. I switched to the 8400s, and they were there like it should have been. I'm not a bass freak, and I'm very sensitive to bass, but on the 6400s, I was trying to use cocktail party effect to pin point the bass, but I had to seriously listen for it. maybe I received a bad pair? but I'm very happy with my 8400s atm.
 
You should also consider just getting the 8400s because they're not much more expensive, better bass, a noticeable amount of improvement in detail, and superior comfort.
 
tdock's probably going to disagree with me though and say that the 6400s and 8400s have different sound signatures, 6400s has bass, and 8400s don't have that much more clarity, but like everything on this forum, it's what I heard and experienced so all opinions.

 
This is weird because I remember long ago having the 8400 and always complaining about it's bass. I'm certainly no bass-head at all and the 1st pair I had could have been considered bass-light. Once I got the 6400 I had found it sounded a bit different and seemed to have much more present (mid) bass. Makes no sense at all to me! I didn't compare them side by side at the time but I was surprised how much more I liked the 6400 (for my music genres) over the 8400. The treble seemed a bit smoother, more mid-bass and slightly more forward mids. Don't have a clue why or how, but the soundstage on the 6400 wasn't quite as good, but still not bad.
 
When doing A/B comparisons (when I bought another 8400) it was very difficult to tell them apart. It took specific music at times. Sometimes they sounded almost identical, but in music with a large soundstage it was much easier to spot the differences. I noticed this same thing when comparing the HD-600 to the HD-650! Some music sounds the same and on other music it's stupid easy to tell the differences. It's very easy with acoustic music with a larger soundstage. The difference in sound clarity isn't huge and it's mostly noticeable in acoustic music and with female vocals. Female vocals on the 8400 are possibly the clearest sounding out of any headphone I've ever owned. Even topping the Q701, maybe even my DJ100.
 
I made the stupid mistake of getting rid of my 2nd 8400 and for months I missed it. Picked up another and this pair sounded absolutely perfect. No major changes, but my idea was that it was just some random manufacturing variation or KRK made very slight tweaks to the sound to improve it. I also noticed this new 8400 had slightly different packaging. This one had a clear plastic shell inside the box and not the usual white shell. This doesn't mean much.
 
Comparing them now and the difference is very, very easy to spot in any music. My 1st 8400 had painful treble out of the box and on this pair it's not ever an issue.
 
I did A/B comparisons of my 3rd 8400 and this 6400 and the 6400 seems to have more mid-bass and the 8400 more forward sub-bass. Tested that for nearly an hour! The 6400's treble seems less extended and a tiny bit easier on the ears, but not by much. Bad music still sounds bad. The mids definitely seem more forward (sounding) on the 6400.
 
I basically think KRK made two different flavors and it's best to pick out which signature you like most. Right now I mostly find myself listening to the 8400, but 6400 is a little more fun with specific music.
 
For rock and pop music I might pick the 6400. For 8400 maybe classical, ambient, acoustic and anything else.
 
BTW the easiest way to tell the difference between the two is to try them in Skyrim. That bass rumbling sound in caves is MUCH more forward on the 6400. I don't think it's sub-bass. Or maybe the 8400 is just more accurate? Who knows..The biggest difference for me is the soundstage size and clearness of sound with Skyrim. I think my 8400 is even clearer sounding than my Q701!!
 
6400 at times seems a bit smoother sounding, but maybe not. When I had my 2nd 8400 I much preferred the 6400 in Uncharted 2. Now it'd be the 8400 for sure.
 
One thing I noticed is that my 1st 8400 had VERY laid back mids. Maybe it was a lemon, but who knows..nothing sounded off. This 8400 has very good mids that aren't even remotely laid back, but more so than the 6400.
 
Right now i'm perfectly  happy with my newest 8400. It's a keeper. 6400 I still own, but don't use as much.
 
BTW like my DJ100, the 8400 really improves with a good desktop amp and computer DAC. The E9 actually works well with the KNS-8400/6400 despite it's 10 or so ohm output.
 
I think the 8400 is worth the extra money and I believe it's often down to $130 or so. I even think it sounds better than the SRH-940 and K550!
 
Best advice is to try both if you can demo them at Guitar Center. I guess it all comes to to preference and music genres. Comparing the two is like comparing the K601 to the Q701.
 
Also..if you check old reviews there's another guy online that claims his 8400 (very early pair I believe) had "scooped out mids". I wouldn't agree with that at all, but my first pair definitely had relaxed mids, not upper mids. I would not say recessed. It sounded like the Koss A/250, but with less forward mids.

 

[Zophiel]

Quote:

The impedance and sensitivity readings for the KRK6400 are somewhat misleading, as is often the case with phones. The 6400 sounds relatively quiet for any given volume setting.

They come in quite low, actually at 95 and 97 dB/1mW for the 6400 and 8400 respectively.  With 95 dB/1mW, you would not be able to produce a peak volume of 110 dB without an amp given an ipod classic as a source, for example more like 106 before clipping. 110dB peak volume translates roughly (changes a LOT with how compressed your audio is) to an average volume of 77.8 dB, which would be considered a "loud" listening volume. (conversation is at 65 dB and hearing damage starts at 90 for extended exposure).  

 

[AnthonyMcEwen]

Sorry to necro an old thread, but just ordered a set and they will be Jere Saturday....

Cpulds not stretch the budget to a 8400 so ended up with these but its my first ever set of proper headphones so I think I won't be complaing about them or anything.

I also (for when I am out an about) ordered a set of £6 JVC Haeb75s lol....will be instresting to see if I can tell the diffence between them with my untrained ears.

Just can't wait to try them.

 

[Nox Mahinay]

My krk 6400 earpad cushion started to peel off, and there are no available replacement parts here in the philippines that's why I did this DIY project . Stock foam and the oval shape thin plastic under the earpad cushion(whatever you may call it) are still in use on this project. As an alternative cushion cover, I used a .40mm thick soft brown genuine leather from a belt bag. and the rest are self explanatory.
 
But I will still consider buying original replacements for this headphone, maybe online. 

 

 

 

[Kalius]

  My krk 6400 earpad cushion started to peel off, and there are no available replacement parts here in the philippines that's why I did this DIY project .
 

 
May I ask you... how long did they last until they started peeling off? 
 
I am after some headphones that isolate sound well enough for the office I work in (passively), and it seems these cost now 79€. Does anybody know some good-sounding headphones under 100$ that isolate well enough and are comfortable with glasses? I checked the ATH-M40x and I heard these are good, but had the ATH-M50x and the clamping force was too tight for me.

 

[CrveniFlash]

I had KRK KNS 6400s for over 3 years,used mainly to produce mix and master (no room for monitors) and they served me well, they are amazing cans when it comes to mids and highs but bass not so much, bass is there and it goes low but its very thin and shy, no punch what so ever, always had trouble mixing bass in the end had to mix it on $7 ear buds lol
And also sound stage aint half bad lol considering they are closed back.

Amps dont make much of a difference tho, still have to try them on Tube amps
Amp used ( Magni 2 connected to Scarlett 2i4 2nd gen )

When it comes to comfort cups are great no complains there but headband is just awful, after 30 mins i could feels burns on top of my head

Conclusion:

-If you produce EDM music dont buy these bass is very Bass shy
-If you are just casual music listener dont buy these they are boring meaning they are Flat, but if u prefer flat go for it
-If u use headphones for long periods of time make sure u order KNS 8400 pads trust me!
-In this price range i dont think there are better cans then these, they even sound better then $150-200 price range cans!!
-Price goes up and down, up and down, i got em for $90
-Are they worth the money? Id say YES!