I'm usually wary of products that come with flashy celebrity endorsements, so I was pleasantly surprised to find that Monster Cable's Beats by Dr. Dre headphones are not just expensive ($349.95 list), they're also impressive. The Beats run on two AAA batteries and produce some seriously deep bass response, along with active noise cancellation, which is passable but not strong enough to compete with big boys like Bose or Creative. The low-end response of the Beats, however, puts them in a category of their own. Bass fiends: Your high-end headphones have arrived.

The comfortable, circumaural (with cups that seal off the ear) headphones are mostly black, with a red lowercase "b" on a white background for each ear. They fold up into a sturdy but large black carrying case, which also houses the two included cables—a red cable for standard audio sources and a black cable with an in-line mic and answer button for cell phones. Two AAA batteries are included, along with a red cleaning cloth and a quarter-inch gold adapter for sources with larger headphone jacks. The headphones have a power switch that needs to be activated to listen to music; there's no passive mode. When powered up, the set offers acceptable noise cancellation, eliminating much of the lower ambient sounds but creating a bit of a high-end hiss commonly heard in cheaper noise-canceling pairs. The "b" logo on the right ear cup acts as a mute button if you want to hear something without taking the headphones off—just hold it down to silence music and disable noise cancellation. The Beats' true asset, however, is its audio performance.

The headphones offer intense low end. I put them through deep-bass boot camp, and they passed with flying colors—every track from The Knife's Silent Shout sounded excellent, with thumping drum machines and resonant synth done justice. Only Thom Yorke's Cymbal Rush provided enough thump to cause low-end distortion, but this occurred only at the very highest volume.

Our Head Acoustics frequency response tests show just how much more bass response the Beats exhibit than my all-time favorite pair of headphones, the Grado GS1000. The left-hand side of the response curve represents low frequencies, which are clearly boosted, particularly in the 30-to-50-Hz range, where most of the deep rumble that subwoofers handle exists. More bass doesn't mean a better pair of headphones, but for those who crave an extra helping of low-end, the Beats serve it up—gracefully. There is also a spike in the1-to-3-kHz range, which makes for some extra-crisp vocals—but sometimes the pair seems a bit too bright. Our linear response test shows that the left and right earpieces are not perfectly matched, but getting an accurate read on just how much they differ is harder with a pair of headphones than with earphones that sit in the ear canal. Still, the difference is not damning and probably has more to do with headphone placement than with the quality of the drivers.

If the price of the Beats by Dr. Dre is too rich for your blood but you still want some serious low end, check out Radius's Atomic Bass earphones. For $40 they're a sweet deal, even if you don't get noise cancellation. At $350, the Beats are no bargain, but they do offer decent noise cancellation, intense bass, a comfortable fit, and they look pretty cool.