Searching for an earbud with the bass of a full-size headphone? Check out Headbanger Audio's Ear Subs.
Ironically, the tiny manual that accompanies the Ear Subs trumpets their Speed Chamber Ergonomically Designed Earbuds, but the only speedy thing about getting these buds in place was flipping the power switch on the tiny subwoofer (located on the audio cable halfway between the jack and the earpieces). The earbud shafts, flimsy little rubber things that cover the speakers, feel quite comfy once you get them in--but good luck with that. The right-side earpiece kept falling out, even when we tried an alternate earbud shaft (maybe we just have weird ears at CNET). This makes head movement difficult, ruling these out as the ideal pair of earphones for the gym. Also, the weight of the subwoofer will pull the buds right out of your ears if you don't use the provided neck lanyard or clips.
We regret the absence of an on/off switch for the subwoofer--being able to turn off the heavy-bass function would make these earbuds more versatile. As it stands, these earbuds are a one-trick pony. That one trick, of course, is creating rumble, and they do that quite well, given suitable material. A caveat: Do not use the bass-boost function on your music source (for example, your CD or MP3 player) with these earphones--things will get ugly quickly.
The Ear Subs particularly shined on the hip-hop/electronic artist M.I.A.'s song "Pull Up the People." The synth lines buzzed with clarity in the low mids, while the underlying low end had an intensity that headphones rarely provide. We had similar positive experiences with just about any explosion in Star Wars Episode 1: The Phantom Menace, but when we tried to listen to Bob Dylan, The Decemberists, or some Stravinsky, the boomy sound threw the delicate balance of these less bass-heavy mixes way off. Applied to the right source, the Ear Subs offer an enjoyable listening experience--provided you don't move around too much. And considering that the 'phones cost just $30 to $40, their limited range is not a huge negative. You'll just want to have a different set on hand if you listen to a wide variety of music and other kinds of audio.