Recently I was looking for a set of in-ear buds after leaving my last Ety' ERP 4's in an airplane seatback after flying MIA-LGA-Mexico the same day. This is not the first time I've left audio stuff after landing groggily in some distant place, so this time around I decided to look for value: a great sounding set of buds at substantially less than I paid for the Etys (when I bought them they were $250).
I was intrigued by the AT ck9's when I saw them discounted from $299 to $144 since they don't get much coverage, and they are part of AT's "Import Line". I took the plunge a & have to say that for $144 I am very pleased with these buds.
I have been using them with my Supreme Headroom amp, and directly with my Zune and my laptop's soundcard output. My initial impression was that they were very bright, and the bass was weak. After playing around with the silicone buds and getting the fitment just right, the bass improved substantially, but is still less pronounced than ideal.
The sound is airy, clear, tight, and bright, with a bias toward high-mid and high frequencies. They are comfortable (I've had them on for the past few hours as I type now) and the sound is not tiring. These buds ocassionally highlight nuances I'd previously overlooked on tracks I've heard many times which makes them engaging. They are as good as or better than any earbud out there for under $145. However at $299 they would have been overpriced. Overall I'm pleased...these will serve me well for portable listening as long as I don't overlook them at the bottom of a seatback pocket.