A typical pair of headphones from Sennheiser will focus on rich, but measured, bass response and crisp highs—and the visual design may look more utilitarian than luxurious. So, it's interesting to watch the company add a little bit of variety to its formidable line-up. The Momentum On-Ear (229.95 direct), like its over-the-ear cousin, is an eye-catching pair of headphones. The sound signature here is more about boosted bass than flat response, but there's a steady balance that is maintained—things never seem overwhelmingly in favor of the lows. The performance is clean at high volumes and the headphones are comfortable over long listening periods. The Momentum On-Ear is worth the high price for those seeking added low-end presence without veering into Beats-level bass boosting.

Design
Available in six color schemes (black, blue, brown, green, ivory, and pink—with varying cable colors depending on the model), the Momentum On-Ear looks, unsurprisingly, quite similar to its around-the-ear Momentum cousin. Both of these headphone pairs are a departure, from a visual design standpoint, for Sennheiser, a company whose headphones have always been firmly rooted in the black-and-gray plastic, chunky world of pro-audio gear.

The supra-aural (on-ear) Momentum adjusts its fit by sliding the earcups up and down, rather than having moving parts and adjusters built-in to the headband. This keeps the overall look simple and clean. With leather accents on the headband and plush earpads made from a material called Alcantara (it feels like felt or velvet, but doesn't seem to get very warm over time), Sennheiser's design implies luxury without ostentation. The on-ear design is pleasant in both look and feel, but it's worth noting that if you were to take this pair to, say, a noisy coffee shop, it's not going to block out much outside noise.

The Momentum On-Ear's cable is detachable (it connects at the left earcup), which adds value to the pricey headphones, as it's much less expensive to replace a cable than buy a new pair of headphones if the cable begins to malfunction down the road. Even better, two cables are included—one with an inline microphone and three-button remote intended for Apple iOS devices.

Also included is a handsome, protective zip-up  case. While the case feels nice, the headphones don't fold down flat into it. Bringing the Momentum On-Ears in your bag will eat up a lot of space, despite them being a fairly manageable size on your head.

There's also a less bulky drawstring nylon bag, though it will still require more space since the headphones don't fold down. Strangely, there is no ¼-inch adapter for larger headphone jacks, nor an airplane jack adapter—an annoyance, but hardly something a quick trip to Radio Shack can't solve for very little money.

Performance

On tracks with intense sub-bass content, like the Knife's "Silent Shout," the Momentum On-Ear does not distort, and it delivers a rich, robust low-end. These lows are matched with a healthy presence in the mids and highs, so balance is well maintained despite the  considerable low-frequency push.

Baritone vocals in Bill Callahan's "Drover" his get a significant boost in the lows and low-mids. This could end up making the mix muddy, as the constant drumming on this track also receives a powerful bass boost, but the Momentum On-Ear adds just enough crispness and bite in the high-mids to maintain definition. Regardless, purists might find this pair a bit too bass-boosted, and the overall sound signature could use a bit more high-mid presence.

On Jay-Z and Kanye West's "No Church in the Wild," the kick drum loop has a sharp attack that slices through the mix nicely, while the sub-bass synth hits that punctuate the beat are delivered with plenty of gusto. The balance here sounds a bit more even than it does on the Bill Callahan track, where the lows get a bit too much boosting and the high-mids not enough. To call this a bass-lover's pair in the era of Beats by Dr. Dre would not be completely accurate.

If the styling of the Momentum On-Ears isn't for you, but you're still looking for some added low-end, the $299.99 KEF M500 is a solid, but pricier, option. Also stylish, but decidedly non-traditional in appearance, is the Marshall Monitor ($200), which offers a fantastic overall balance with a bit more brightness (when you take out the removable dampeners in the earpads). For more modest budgets, both the $100 LSTN Fillmores and Sennheiser HD 429s ($89.95) offer solid audio experiences, the latter providing a more typical Sennheiser sound signature for a far lower price. For $230, however, the Momentum On-Ear delivers a frequency response that will appeal to those seeking added bass without overwhelming the mix—the comfortable design and detachable cable only sweeten the deal.