Koss earbuds don't have the most outstanding history on CNET, but they haven't utterly failed either. Still, they have tended toward the middle of the road, which isn't bad considering their low price point. Now, Koss has made a brief departure from ultracheap 'buds to release the KEB/79, a $100 pair that purports to offer "deep bass and unbelievable isolation." Unfortunately, for some users, problems getting and retaining an effective seal with the ear may interfere with this claim. Still, the KEB/79 is quite capable of producing quality sound, if you can achieve a proper fit.
The design of the Koss KEB/79 is my main gripe, though there are certain aspects that I appreciate. First, the cable is modular, so you can choose between two lengths: 17 inches for use with an MP3 player that you carry in a shirt pocket or wear clipped somewhere on your upper body, or add the extender to get to 58 inches for use at home or with a player that you carry in a bag. Another nice touch is the inline mute switch, which you can press and hold if you want to hear external sound without taking the earbuds out. It's cool that you can press it in the middle for full mute, or on either side to just mute either the left or the right channel. I also like that Koss includes a pouch for storing and carrying the earphones.
However, the mute switch and cable connection also cause part of the problem with the KEB/79: they add weight that pulls on the left earbud, causing it to gradually slip out during activity. Plus, it can be difficult to achieve an adequate seal with the ear to begin with. Koss includes three sizes (small, medium, and large) of silicone ear tips, but I couldn't even get a good fit with the smallest ones and was never able to bring about effective isolation. And unlike with competing models from the likes of Shure and V-moda, the ear fittings rest flush with the 'bud, meaning the hard plastic casing sits inside your ear as well. This low-profile design is good for looks, but I found that this contributed to my problems getting a seal with the ear, and it proved uncomfortable after less than 30 minutes of wear.
Of course, not everyone will have this issue with fit, and users that can get an effective ear seal will be rewarded with good sound quality. Initially, music came off as bright and lacking in bass, but once I pressed the KEB/79s into my ears, things improved considerably. The high-end clarity is not the best I've heard, but it's up to the $100 standards. Really, the mids and lows shine the most through the KEB/79--you can even pick up upright bass in track backgrounds. Overall, folk, classic rock, blues, and dancey hip-hop sounded best, but the headphones do a fine job in general.