[GoldenboyXD]

   
I was just summarizing what some users on MD stated on their site.
 
I just tried my K7XX with my motherboard headphone jack, the only low power amp I have, and noticed the flapping noise caused by cone breakup at 82% volume. I was using a 30hz test tone in audacity with amplitude at the default value of 0.8 to prevent clipping. I then tried my Audio Technica m50 and it didn't have the flapping noise even at 100% volume. The m50 is more sensitive than the K7XX since it was louder than the K7XX at 82%. The flapping noise on the K7XX seems to happen up to around 55hz.
 
It does seem like the K7XX has a problem with sub bass causing cone breakup at high volume when other headphones can play them just fine. Has anyone else experienced the flapping noise with frequencies below 50hz on their K7XX? I don't think 20mW of power is considered an extreme amount. It would be great if more users can test their K7XX to see if they have the same problem. This is not to be confused with the rattle problem that others have complained about.

I would also consider this as the "rattling sound" of the driver. It happens on 55hz and below. Well, in addition to this... Some will say that these HPs are not meant for bass heavy music and some will say that it should not happen and those are factory defects. I say that it's a matter of enjoying your HP and burn-in more (not breaking it) until it loosens a bit. 
 
Also, some amp probably makes this HPs rattle and some are not.

 

[kman1211]

 
I just tested it on my ODAC/O2 combo, both 1x and 2.5x gain, and the K7XX made the same flapping noise while the m50 played it perfectly fine even at a higher volume. I have well over 200hrs on the K7XX.

It could be a variety of things, could be defective or it could not like the amp. Have you taken the pads off to check if the driver is crinkling when the flapping noise occurs? 

Interesting. But I actually do not know whether the K7XXs are tantamount to the K712 Pro. I do not possess the latter, so I am hoping for some more comparisons.

I do like the K7XXs with most of my music so far. They are just heavenly with film soundtracks and most of the electronic music Ive tried. That peak though...

That is true, I likely wont be able to try the K7XX for a few weeks or months, it all depends when my friend plans to send her K7XX for me to audition. From what I gather the K712 and K7XX sound different and seem to like different systems more. 

 

[superballz00]

  It could be a variety of things, could be defective or it could not like the amp. Have you taken the pads off to check if the driver is crinkling when the flapping noise occurs? 

 
I don't know if I would call it crinkling but it is moving a lot like the one in the video. It makes the same sound as the K7XX in the video. The Q701 in the video also moves a lot but doesn't make same noise.
 
https://www.youtube.com/watch?v=B4_DSyGc3Y4

 

[donunus]

That does help. I have the K7XX and like it very much but feel a shouty peak more exorbitant than my Q701. With some tracks, however, they become nearly painful. Thus, I am eager to know what you conclude.

Thanks,

I have a feeling that peak will go away after a while because although my Q701 still has a little 2khz peak, it is nowhere near as annoying as they were out of the box.

 

[donunus]

The rattling issue also improves with burn in but nothing will ever save the distortion if the cans are underpowered.

 

[marts30]

I don't notice a peak at all, certainly nothing painful! HD800 on the other hand, ouch.

 

[mrscotchguy]

I figured I would chime in since I ordered this and it came in a few weeks ago.  Ended up with at 15xx serial number.  I cannot be more happy with the $200 that was spent.  These are certainly on the warm and musical side of the spectrum.  For whatever reason, I have never been drawn to this sound signature, but the vocals are so forward, that it has been super fun re-listening to all my old music.
 
Oddly enough, of all my configurations, the K7xx sounds best directly out of my ipad4... it has become my easy-peasy bedroom setup. 

 

[pearljam50000]

Its not fair they don't ship internationally ):

 

[donunus]

   
 
Oddly enough, of all my configurations, the K7xx sounds best directly out of my ipad4... it has become my easy-peasy bedroom setup. 

Sure it may sound okay but is it really loud enough for you?

 

[ayao]

I just realized that my K7XX also has the rattling issue, but I don't use them at such high volume levels so it's not a problem.
 
https://www.youtube.com/watch?v=qNf9nzvnd1k
Using this frequency sweep, my left side rattles from 20-24hz. My Xonar Essence STX Audio Center has its volume set at 32 (there is no rattle @30), and I'm using the extra high gain setting.

 

[mrscotchguy]

Sure it may sound okay but is it really loud enough for you?

I usually only go 9 or 10 clicks of the 16 on my iPad. It's also not good to listen to headphones much louder than that for 4-5 hours at a time. All my other setups cause the k7xx to sound mushy and the bass muddy. These are not hard to drive. I need to try them directly out of my AQ Dragonfly still, but they certainly do not like a warm source.

Btw, does anyone know a service who will balance these headphones?

 

[plakat]

Most reports still sound to me like overpowering a driver not built for strong bass... If it happens way above your normal listening level -- who cares? Relevant cases are distortion at normal listening level.
 
I still think many of Massdrops customers were expecting something else entirely...

 

[earplug]

I just found out that Massdrop doesn't do returns for these headphones. Nothing wrong with mine. I just need the money for some computer parts. I guess mine may go on the For Sale forums if I decide to sell.

 

[Colgin]

  I figured I would chime in since I ordered this and it came in a few weeks ago.  Ended up with at 15xx serial number.  I cannot be more happy with the $200 that was spent.  These are certainly on the warm and musical side of the spectrum.  For whatever reason, I have never been drawn to this sound signature, but the vocals are so forward, that it has been super fun re-listening to all my old music.
 
Oddly enough, of all my configurations, the K7xx sounds best directly out of my ipad4... it has become my easy-peasy bedroom setup. 

Interesting.  I found that my Q701 seemed pretty underpowered from my IPhone/IPad even though I could get somewhat reasonable volume, so it never even occurred to me to try the K7xx out of my Ipad the one time I tried them. (My K7xx are currently boxed up in case I decide to keep the Q701 over them. I don't want to keep both, so I am trying to keep the K7xx as minty as possible and have only used them once, but liked them quite a lot.)  But if I decide to keep them I will definitely given them a try out of my Ipad. It would certainly be nice to have that as an option.

 

[kleefurd]

 
Interesting.  I found that my Q701 seemed pretty underpowered from my IPhone/IPad even though I could get somewhat reasonable volume, so it never even occurred to me to try the K7xx out of my Ipad the one time I tried them. (My K7xx are currently boxed up in case I decide to keep the Q701 over them. I don't want to keep both, so I am trying to keep the K7xx as minty as possible and have only used them once, but liked them quite a lot.)  But if I decide to keep them I will definitely given them a try out of my Ipad. It would certainly be nice to have that as an option.

The K7XX are really something, aren't they? More than just novelty, I think the tweaking that has been done to the voicing of the headphones makes them really one of a kind from the AKG stable and personally I think they are best kept as a collector's item. Been a while since I have enjoyed a AKG cans so much.