That's strange. My pair is very, very clear. It even competes well with a lot of my other more expensive headphones in this area. I'm really picky about this too. I've noticed that with my pair it can often make a specific song sound like garbage since it's quite revealing (but not overkill). Today I was listening to a CD I purchased 6 months ago that just came out. I heard it a hundred times by now and for the first time I heard some pops and static like sound in the background of a song. Certainly wasn't my mp3 player! It's amazing that we can still have all that in a CD that was recorded just a few months back. Obviously most people won't hear it.
I tried these for Fallout 3 the other day. They sounded considerably less clear than on the K501 and HD-598. What the heck? In the end I just felt that it was because my KRK was just more revealing of how bad and compressed some of the sounds in that game are. Many of my headphones are good at making some bad music sound good or decent! I put on my fully modded HD-668B and it sounded just as bad! The HD-668B is a super clear headphone with a ton of detail when modded. Often the sound clarity of the KRK KNS-6400 varies from song to song, but this is just my case. I clearly remember one day switching from another headphone and then to the KRK and thinking "This isn't so clear!". I just figured that the song in the end just was a lower quality track and the other headphones made it sound quite listenable.
It could be you have a goofy pair or it needs more burn-in. My pair didn't need any burn-in in, but my first 8400 did. Maybe you can exchange for another if it doesn't clear up?
As for the pads, you just pull them off and then when putting on the new pads you click them in place. There is a bunch of tabs around the pads that you need to click.
Here's an old review I did of my comparison of the HD-598, Sextett, 7506, DJ100 and the KNS-8400. Might be interesting for some! The 8400 came out on top when it came to sound clarity, which was even a surprise for me.
The 8400 is slightly more clear sounding than the 6400. We're talking like 2-3% better and ONLY with specific songs. It took me FOREVER to tell the difference. It required a song with just acoustic guitars and a large soundstage in the recording. I think one could only tell the difference if they were comparing them side by side.
Another strange thing I realized today is my 6400 straight out of my Ipod Touch needed to be at nearly 90% volume!! Now I don't think it requires an amp, but it's pretty interesting. I wonder how these sound out of my iaudio 7. I'll have to try that!
I took the 6400 apart yesterday and KRK looks like they really know their stuff. I was going to take some pictures, but didn't. They actually put dampening material over the back of the driver (looked like super thin felt) and then put some sort of shell over it with a fabric covered hole. Now I just need to figure out why there is 4 vent holes on the left of the headphone and only 5 on the right. There must be a reason for this. Anyone know or have a guess?
I think a recable is still possible after all, but I'm not about to try it since it needs a ton of work. I think the KRK cable is probably quite good enough already.
Thank you Tdockweiler for the detailed review.
I am not sure why, but I found that my pair has left much to be desired. The clarity is lacking far behind my Sony MDR7506 with DT250 pad mod, it is like we are talking about different phones. The fact that the two pairs of 8400 of Tdockweiler has a slightly different sound makes me wonder if the QC of KRK is adequate.
Hopefully this is a run-in issue which will sort itself out overtime.
BTW how do one remove the original pads and replace with the 8400 pads ? The pads with my 6400 seem pretty secured with the phones.
Edited by tdockweiler - 8/26/11 at 11:20am