ER-6I was broken recently so I decided to try out audio-technica’s inner-earphones, ATH-CKS70. My first impression was “not bad for its price”. Its got a sub-chamber to emphasize bass quality and surely got powerful bass for its size.

However, treble lacks resolution compared to ER6i (I’ve recommend setting iPods EQ to treble boost) .  And I couldn’t find any difference in two position post ear piece system.  Personally, I’m kinda afraid whether if its leaking sound or not.

Anyway, ER6i costs about twice of ATH-CKS70 so its not a good practice to compare those two.  But as a medium range earphone, I think ATH-CKS70 is one of the best in its kind.