This is the second BBG review of Audio Technica headphones, following the active noise canceling ATH-ANC3s (which I loved). In contrast, the ATH-CK7 are a noise-isolating set. They proved to be a very good product, and an instructional one.My observations while testing the ATH-CK7: 1. I know what impedance does now. Impedance is one of those words that seems terribly important to stereo salesmen but makes no audible difference at home so long as your speakers and components are decently paired. In portable headphones, impedance takes on a much different bent, because it ultimately affects the volume of a device's audio output. High impedance levels make it hard for, say, an iPod to provide the right power to the headphones. When I first tried the ATH-CK7s, I was cranking the much volume higher than I'm comfortable doing, which confused and concerned me. Then I did a bit of reading and discovered these headphones have a 90 ohm impedance. Ninety is way high: Apple's standard iPod earbuds have an impedance of 32 ohms. (The Audio-Technica ATH-ANC3s have the same impedance as the CK7, but the power boost of the active noise canceling compensates for it.) Thus informed, I cranked up the volume dial. 2. Audio-Technica loves bass. Specifically, they're big on replicating the good low-end thump one gets from a home or car stereo in their headphones. This is a markedly different technique from companies like Etymotic and Shure, which aim for reproduction accuracy first and foremost. Me, I like bass, so the ATH-CK7s made me happy. Audio quality is good across the board, but the ability to get hearty low-end at low volume levels makes a difference. 3. Headphones have learning curves. I brought these headphones on a family vacation, and traded with my music-loving relatives, who had over-the-ear Bose noise-canceling headphones. I figured the hearty bass response of the ATH-CK7 would be an interesting variant to the cleaner Bose sound. Two people tried them, and both returned the headphones to me with scrunched noses, saying: "They're tinny." Which, to me, was crazy: the ATH-CK7's bass is as good as any of the models I've tested. But I had the large-size silicone ear cushions in place, and I didn't show my relatives how to make a seal to maximize bass response. I'm used to it, but noise isolation definitely requires an instruction manual. As for the headphones in question, ATH-CK7 is a solid performer, best at minimizing distortion. It's a moderately good noise isolator, although the active noise canceling in the ATH-ANC3 blows the CK7 away (excluding wind, that is). They're also quite comfortable to wear. I'm 2 for 2 in enjoying Audio-Technica's headphones.