Burning in the AKG K701

FYI the XB500s are not K701s.

My K702s have a good hundred hours or so, and I haven't noticed too much of a difference. If anything, there's a bit more bass but it's nothing drastic or overly noticeable. I think the K702s have a lot of potential, though. Perhaps I should order an aftermarket cable for them.

I'm aware of burning in speakers and the effects that are achieved.  This has been documented a bit in the speaker community by Danny Richie of GR Research.  I'm sure headphones also respond accordingly to burn-in.  Speaking of the AKG 'phones, has anyone modified the headband to remove some of the "hoop" in the metal?  I don't have a big head (I guess I don't have a big brain either), but it seems like I'm a martian or something with all that extra metal on the rings above my head.  I guess I could easily take off about 3/4" on each side and take these down to size a bit - and the metal would be closer to the head strap.  If anyone has done such a mod, I'd be interested in seeing, hearing or reading about it.  Thanks,

I Currently own and still use a AKG K701 with my own modification to soften the blow to slight degree while still retaining the overall character of the music reproduced. 

From my experience, the AKG K701 requires more than 300-hours to fully burn-in and settle down to what I would call the settling phase.  In this phase is like listening to headphones in it prime state.  And from what I can hear, the prime state is now for my K701 since June of 2009.  Now mind everyone here I had to change the stock foam dampers with something I concocted and is surprisingly great with this headphone.  The stock cable is currently being used since I still need to retain the flexibility that the cable offers. 

Before the modified foam dampers and after the burn-in phase, the treble frequencies can be rather bright and harsh.  It is very airy, however the bright and sibilant nature is something that my hearing can't tolerate.  After the modification, the sibilance is gone while the airy nature is retained.  The sound stage is brought closer to the listener, while the details are still revealed with all of its resolution of detail.  The bass frequencies reach a little further down while still remaining to be punchy and tight.  Organ notes are brought out with virtually no emphasis of any kind while listening to Jennifer Warnes Famous Blue Raincoat, her voice is suspended in front of the listener while the instruments float just behind her as though I am basically sitting in at the recording session as a neutral observer. 

Give it a little bit more time and many listeners of the AKG K701 will reach the prime phase of the headphones at which one could be able to listen to sound that these headphones exude.

Hope this helps

I remember mine settling after 200 hours.  Bass does come out a bit more, but nothing drastic.  It extends a tad deeper, but the impact and sheer volume of it still lack.  Midrange becomes a bit more natural, and detail/soundstage get a little bit better as well.  Having said this, the K701 will always be bass lean and rather bright.  Burn only changes the sound ever so slightly.

@fredPB

Couldn't tell you about burn-in since I purchased my pair used, but I will say that it's easy to find the bass impact lacking on these phones, this may not change with burn in.  They teeter between lacking and satisfactory, usually closer to satisfactory.  No amount of detail resolution lacking on my system though, so you can probably look forward to that changing.

I find this is a very interesting psychological question. I am sure that we can perceive sound signature changes in critical listening with new headphones, but are these changes real, or is it just that our brains are adapting to the sound of the new headphones. Moreover, if sound quality improvements are expected during burn-in, most likely changes will also be heard, whether it happens or not. We humans are not that good at "referencing" sounds we hear. Therefore it is also very difficult, or even impossible, to dispute burn-in.

Actually, when I decided to purchase my new K701s over a week ago, I contacted AKG via their email-hotline. I wanted to know what their thoughts on burn-in were before I would begin listening to the changes first hand. Couple of quotes from AKGs response:

"From our experience and knowledge we cannot confirm that there is a burn in effect of the transducers taking place."

"However, during the first hours of use of headphones, the ear pads -  in the
beginning a little stiff – start to accommodate to the users ears and head
and the sealing becomes better, as a result the bass can be increased a
little, on the other hand the distance between the headphones and the ear
may become closer, i.e. fewer air volume between ears and headphones is
available and thus less bass."

I have also ordered Alessandro MS-2s from their website (still waiting for them). So I also contacted Grado and asked the very same question:

"there is NO scientific evidence that a prolonged "run-in" is beneficial. In fact we don't recommend it. We recommend that one uses there headphones normally, there will a "loosening" of the suspension after a period of time and it will settle in ( the material do follow Hook's law). those who run in their headphones for a prolong period of time risk damaging them. after a "workout" the drivers must rest, just like going to the gym you have to rest your muscles."

I personally do not believe in physical burn-in. Transducers do their thing millions of times in a of couple of hours. I have not heard any changes with my K701. I have about 25-30 hours on the headphones. This of course does not prove that there are no changes. Someone who has better ears than me could possibly hear them, no doubt. I don't think there is right or answer on this one. I am eagerly waiting for the MS-2s to arrive and I will again carefully listen if I can hear any burn-in.