[3h0i3]

So I have a pair of 8400s and I love the fit/ambient isolation/inline fader, but the sound...not so much.  I find the upper mids and mid highs abrasive.  I'm no basshead, I was using AKG 271 or 171 before this, and both those are known for their "lean" bass, but these krks seem to lack bass even more.
 
I've never done burn in, but I figure it is worth a try to make these listenable.  I usually listen to my music at a very modest level, usually just the first notch on ipod touch level, or 2% on my laptop, but I assume this will never burn the drivers in. 
 
I left the headphones going overnight with my laptop volume at 40%.  At about a meter away from the phones I could hear the highhats, and the 303, snare etc.  I tested to see how loud this is on an ipod touch's volume at it is about 80-90% that I get the same effect.
 
In the morning, I am not sure I notice a significant difference.  There may be more low end prominent, but the upper mids/highs are still just as abrasive if not more. 
 
Now I'm concerned that I may have even damaged the drivers, or are they just not burned in correctly yet?  Would you expect these headphones to be damaged by an ipod touch ran at 100%?  I would think they should be ok with that, and it was not even 100% more like 85%.  These headphones should handle that sort of volume correct?  Don't people use them in amps that go even louder than an ipod touch goes?

Thanks for your insight.

 

[GaryWA]

  So I have a pair of 8400s and I love the fit/ambient isolation/inline fader, but the sound...not so much.  I find the upper mids and mid highs abrasive.  I'm no basshead, I was using AKG 271 or 171 before this, and both those are known for their "lean" bass, but these krks seem to lack bass even more.
 
I've never done burn in, but I figure it is worth a try to make these listenable.  I usually listen to my music at a very modest level, usually just the first notch on ipod touch level, or 2% on my laptop, but I assume this will never burn the drivers in. 
 
I left the headphones going overnight with my laptop volume at 40%.  At about a meter away from the phones I could hear the highhats, and the 303, snare etc.  I tested to see how loud this is on an ipod touch's volume at it is about 80-90% that I get the same effect.
 
In the morning, I am not sure I notice a significant difference.  There may be more low end prominent, but the upper mids/highs are still just as abrasive if not more. 
 
Now I'm concerned that I may have even damaged the drivers, or are they just not burned in correctly yet?  Would you expect these headphones to be damaged by an ipod touch ran at 100%?  I would think they should be ok with that, and it was not even 100% more like 85%.  These headphones should handle that sort of volume correct?  Don't people use them in amps that go even louder than an ipod touch goes?

Thanks for your insight.

I think that is just the headphones sound signature. In this review, he also states the treble is harsh, and the bass light, but it stayed that way as well.
 
http://www.head-fi.org/t/526400/krk-kns-8400-review-impressive-150-headphone
 
You might want to try some different headphones, perhaps some with a warmer treble.

 

[kraken2109]

There is no evidence that burn-in on headphones is real, and if it is it's so subtle it isn't going to make you like headphones that you didn't already like.

 

[manbear]

iPod at 100% isn't going to damage your drivers. Don't worry about that.

While people may argue about whether or not burning in makes a subtle difference, there is no way it's going to turn a headphone you don't like into one you do like. In fact, burning in may just be a myth created by manufacturers to get you to miss the deadline for making a return. Don't fall for the trap. 

 

[3h0i3]

Hey guys.  Just so you know, I contacted KRK and they said there is no burn-in period for their headphones.