Pros: Very small, light, and comfortable
Cons: Poor isolation, awful cable, no cable cinch, non-standard nozzle shape, very mediocre sound
Accessories – Single-flange silicone tips (3 sizes), detachable ear inserts (3 styles), and soft carrying pouch
Build Quality – Housings are made of metal with oval-shaped plastic nozzles and paper filters. Though strain reliefs are excellent all-around, the cabling itself is hugely disappointing (especially compared to the excellent cables on Audio-Technica's higher-end models) – thin, rubberized, and extremely prone to kinking and tangling
Isolation – Poor due to shallow insertion and vented design
Microphonics – Cable is too energetic and tends to bounce around a lot. Lack of cord cinch and shirt clip means these have to be worn over-the-ear to be usable
Comfort – Small, light housings make them very easy to wear. The rubber ear inserts can be used to further stabilize them but aren’t necessary
Sound – Unfortunately the ATH-CK6 is decidedly underwhelming when it comes to sound quality. The bass lacks extension, is boomy, and becomes somewhat muddy on dense tracks. There is no definite moment of impact, which results in drums sounding too soft and at times hollow. The midrange is veiled and vocals lack both presence and smoothness. Treble is harsh and tiring. The entire signature lacks clarity and resolution. On the upside, they don’t sound closed and soundstaging is better than average. A small consolation but it made listening to them for a few days bearable.
Value – I wanted to like Audio-Technica’s mid-range offering, I really did. But like the oh-so-popular Sennheiser CX300, the ATH-CK6 is an old model, and it shows. Compared to the dozens of other IEMs I've heard in the price range, the CK6 suffers from mediocrity on all fronts, from isolation to sound to build quality. All things considered it just isn't a very strong competitor in an increasingly crowded field. The line is due for a refresh anyway and hopefully Audio-Technica will apply at least some of the design principles of their top-tier entries to the mid-range earphones
To see how the CK6 compares to the other earphones in my collection, see here .