I finally got my Audio Technica CK7 earphones . Paid about 90$ including shipping from a reputable (ID verified) ebay seller. 
 
Right out of the box, the highs where a bit harsh and there was a noticeable level of sibilance. This was actually a good sign because all high end earphones I got so far did this before an overnight burn-in. The memorable exception was the fake Sony earphones. I don’t know for sure what is so different in hi-fi earphones that does that but it is probably because they can actually produce such high frequencies while the cheap ones just cut it off anyway.

After an overnight burn in, harshness and sibilance are gone. I checked impedance and everything looks all right. There’s a little bit more difference between the left and right speakers (about 1 Ohm) so it is not as precise as the ER6 Etymotics. One speaker will probably play a tiny bit louder but it won’t be noticeable.

Then the real test began in my noisy work environment. This was not a problem while listening to big noisy music like Hatebreed and Front line Assembly but with classical music, external noise and speaker noise really gets in the way. Since I already have replacement foam tips on order for my ER6, I didn’t mind replacing the provided silicon tips of my CK7 by the Etymotic foams. I had to stretch the opening a little bit but it still fits and it really raises the CK7 to a new level of quality by significantly reducing external and speaker induced noise. That is how I’ll use my CK7: with ER6-14F Etymotic foam tips. It is a small easy to do mod that is really worth it. Note that this mod could be done on the Sony EX90 earphones but because of the vent holes on the buds, it would not be as efficient.

Sound description:

It is still a bit early to provide a detailed appreciation but so far I can say it is not as clear, precise and detailed as the amazing Etymotic ER6 by a long shot. Even the genuine Sony EX90 have much better sparkling highs extension. In the mid-range, it is comparable to the Sony, offering a soft vocal reproduction, which is pleasing while listening to Renee Fleming. The bass is good but not as sharp as the Sony or Etymotic. When pushed to extreme low and highs (Front line assembly with some Mach3Bass and BBe), it gets a bit messy. I think the fully closed design don’t leave much breath to the speakers to express themselves so the sound is a bit muffled (but not as much as with the horrible Sony fakes). The only advantages over the Sony are the possibility to fit the Etymotic foam tips for greater isolation and the lower price. Otherwise you get more details across the band with the Sony EX90.

About the built quality, these are little titanium tanks, no problem there. The provided pouch is very cheap, nothing like the one provided by Etymotic or the outstanding Sony leather case. The wires are nice, not too tangly and quite thick. Microphonics are kept to minimum, especially while wearing the wires above your ear for extra support. 

To make a long story short, at about  2/3 the price of the Sony EX90 or Etymotic ER6, you get 2/3 the sound quality, loosing much details in the process. For exemple, it won`t bring Nina Simone back from the dead signing images just for you like the ER6 can do but it will still be very enjoyable to listen to her through a pair of CK7.



The CK7 is a quality earphone for sure but it doesn’t compete very well with its >100$ competitors. I give it 7/10, very good but nothing to rave about. (I gave an excellent 8/10 to the EX90 and an exceptional 9/10 to the ER6).

EDIT: After re-testing with the provided silicon tips, I found out the Etymotic foam tips increase isolation by a large margin but also contribute to muffle the sound a little bit  (it doesn`t do that on the ER6). Frequency response of the CK7 is better with the provided silicon tips.

 Ok, I’m switching back to my Etymotic ER6 now... These are addictive.