"Atomic Bass" is a tough name to live up to, but these $39.99 (list) earphones from earphone newcomer Radius deliver. They pump out audio with a seriously big bass response—so big that with the volume up on bass-heavy tracks, I felt as if my torso might explode with each heavy drum hit. Audiophiles looking for balance and clarity should stop reading now. But if you're seeking a booming low end in relatively cheap, light, gym-suitable earphones, your wait is over. And, in case you're worried that external sounds might somehow overwhelm the massive bass, Radius has got that covered: These earphones also block out some background noise passively. All this makes them a terrific budget pick for fans of music with a prominent low end.

The 0.8-ounce Atomic Bass earphones can be worn traditionally or with the cable tucked behind the ear. The connection of the cable to the earpiece seems more durable than that of most inexpensive earphones I've tested. Typically, earphones in the sub-$40 range aren't made to last; the Atomic Bass 'phones, while still cheaply made, look just little bit tougher. They're not likely to last far into the next decade, but they should survive most gym outings, if properly cared for.

Audio performance of the Atomic Bass is intense. Whether or not it's too intense is a matter of taste. For example, I love bass and low-end notes in general, but that doesn't mean I want them to be so overpowering that I lose high-mid and high-frequency clarity. There's something to be said for crisp vocals, too! But plenty of people (you know who you are) would happily sacrifice the vocals for deep, resonant bass. And that's exactly what the Atomic Bass earphones do: batter your ears with a thunderous low end that overpowers the high frequencies. That's not necessarily a bad thing: A lot of hip-hop, electronic, and club music is meant to be heard this way—on a system with a subwoofer playing at max volume. The Atomic Bass earphones are essentially the personal version of a maxed-out subwoofer sound.

Our HEAD Acoustics frequency response charts show that the Atomic Bass set overpowers even the Ultimate Ears UE 11 Pro (a $1,150 set) in the low-end department. It's impressive that these small earphones pack so much punch at such a low price, but bigger bass isn't necessarily better bass. Compared with the epitome of flat audio response, the Etymotic ER-4P, the intense low-end response here is even more obvious. Our linear frequency response charts show that, like most inexpensive earphones, the Atomic Bass set lacks consistent output from earpiece to earpiece. Oddly enough, the response is least balanced in the same low-end frequencies that the earphones significantly boost.

No matter what kind of sound you like, if you're looking to replace your iPod's earbuds, don't pay Apple $29.99 for earbuds that deliver $5 sound. And if you're a sound snob, stay away from the Atomic Bass earphones, too; their audio performance is all about the low end muscling out the high end. But if you dig low-end-heavy sounds, by all means consider the Atomic Bass earphones. They'll deliver the intense sonic experience you crave.

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