[kman1211]

Your hairs or other foreign objects getting onto the driver diaphragms can do that.

It wasn't hair or foreign material, I already eliminated that possibility, they were brand new headphones and distorting and I checked for hair, etc. as the first potential issue. I've had hairs in headphones prior, but never a brand new set but I checked anyways. I actually looked at the driver behavior when this was happening, the membranes were physically crinkling a lot on the K612 when there was a decent of bass in the song, there was substantial modal breakup going on, this happened regardless of the system, it was very different behavior than a foreign object in the driver, especially considering it was equal distortion on both drivers, and it went away with heavy and loud burn-in for about a week and never came back.

 

[athlon7750]

Grammy Award-winning recording engineer Rainer Maillard uses the K612 in his studio. Nice.

 

[zeekz]

I grabbed a pair of these for £26..or 20% of the price of a USED Sennheiser HD600 which is £150. Best £26 i've ever spent in my life. Sold my HD600 & K712 after spending 3 weeks with the K612. Kept my HD650 though.

 

[Shoewreck]

Finally, I've received my pair of K612. #022724, finely crafted in China.

To little surprise these are just a facelifted and differently tuned K501. Same build quality, similar construction, similar everything.
Headband adjustment is more restricted. I have a bigger head, so K501 stretch to max. K612 doesn't fit my head well at all. Pads are big enough to fit my ears: bigger than stock K501 and bigger than generic K701 pads I've bought from eBay.
Sound is fine and neutral. Headstage and positioning are great.Vocals are gently brought forward, lows are a tiny bit more substantial than I like, highs sound a bit more natural than K501. I don't experience the famous 2kHz spike at all.
I'd call K612 an upgrade to K501: even if you manage to solve K501 bass issue, K612 provides slightly more natural treble and midrange (just slightly, nothing you can't get used to in a few minutes of listening). And the best of all: K612 sounds right as it is. All of my headphones are modded. These will not be.
The only things I'd regret about K501 is headband (thinner and softer leather and more stretch) and textile pads (not). I sincerely believe that you don't have to hunt K501 as long as you can get a brand new K612. You can always remove the foam rings if you happen to prefer a leaner bass. Still, my K501 is a keeper, the 612 goes to my wife.

 

[Shoewreck]

Regarding burn-in: I'm currently running low frequency sweeps. There was a nasty rattling around 15-20Hz at full volume. I did perform a visual check, the outer diaphragm warped a bit when too much excursion was occuring on lower frequencies. The effect disappeared after a few minutes and did not reappear after cooling down. It seems like the diaphragm edges have reached their design flexibility.
P.S.: it's the same effect @kman1211 has described a few posts earlier.

 

[491838]

I owned the K612 briefly last year and didn't like them. I mean they did sound great for certain genres but for modern music not so much. I found them lacking bass quite a bit compared to the K712. I wish I could hear them again to compare.

 

[markanini]

I picked up the K612 today. Every sound is clear and smooth. Violins, trumpets, cymbals, screaming distorted guitars are well handled. Really juicy. I wore them all day without listening fatigue. 3D imaging is on point. Lacking only a little low end impact and presence but this doesn't take away much from overall aural enjoyment. Easily the best sounding headphone I've owned.

 

[SSandDigital]

I've always wanted to hear the K601, not the K612.

 

[vcmusik]

I happen to be the new owner of a used K612 Pro that I scored on eBay for pretty cheap. I like it a lot more than my K7XX, and find that everything sounds so natural and balanced. It's just a shame they don't incorporate the detachable cable system. I did get these modded by a friend for balanced XLR input, and that made the soundstage expand perceivably even more, which is a real treat.

Something I need help with though: My pair doesn't have the "Made In ____" sticker, and didn't come with a box so I'm not sure if it's an Austrian or Chinese made pair. Short of actually contacting AKG to ask, is there any way I can tell? I have a high serial number of #104109 so I'm just assuming that it's a Chinese batch.

 

[charliex]

Where were they shipped from?
So far I have not heard of any fake 612s out there.

 

[vcmusik]

Where were they shipped from?
So far I have not heard of any fake 612s out there.

Funny enough, I live in California and the seller lives in a city not too far away. I'm not so much questioning their authenticity as just curious where they were manufactured. I've read comments in this thread and others saying that the Austrian-made units sound better and have slightly better build quality, and also vice-versa on other forums as well, so that's what sparked my initial curiosity.

 

[markanini]

Legit AKG products are produced in China like my AKG K612 and other models belonging to mid and low end segments of the line up. Although the switch was made shortly after 2013 when the AKG K612 was introduced so a Austrian made pair would be relatively rare. It's a pretty popular model among studio engineers with demanding requirements yet I haven't heard any reports of major SQ regressions. I still think mine sounds great, regardless of its high value for the price. On the downside I lost right side output after a month requiring me to send it in under warranty.

 

[kid vic]

Legit AKG products are produced in China like my AKG K612 and other models belonging to mid and low end segments of the line up. Although the switch was made shortly after 2013 when the AKG K612 was introduced so a Austrian made pair would be relatively rare. It's a pretty popular model among studio engineers with demanding requirements yet I haven't heard any reports of major SQ regressions. I still think mine sounds great, regardless of its high value for the price. On the downside I lost right side output after a month requiring me to send it in under warranty.

I sold my K612s awhile ago but I'm 90% sure they were made in austria. I actually think that you might have the rarity idea wrong but I'm not sure. Anyways, I didn't notice any physical quality difference between it and my K7XX.

 

[markanini]

I sold my K612s awhile ago but I'm 90% sure they were made in austria. I actually think that you might have the rarity idea wrong but I'm not sure. Anyways, I didn't notice any physical quality difference between it and my K7XX.

Of course you want to think that if your pair didn't have the sticker.
I got my info from a current businesses partner of a former AKG employee.

 

[Shoewreck]

Chinese made units have somewhat rougher edges, but you won't tell until you touch a Euro AKG. Build quality is so-so regardless of origin.