There's actually more to the rather plain and simple looking PX100s than first meets the eye - and in more ways than one. Sennheiser's wallet-friendly travel headphones ingeniously fold, bend and slip into a plastic case of about the same size as the average spectacles case, with the cable wrapping around the outside. Truth be told, I actually find the process a little too ingenious, requiring close attention to be paid to the instructions printed on the back, but it's certainly a step up from leatherette pouch supplied (if anything is) by competing brands.
Unfolded, there aren't many frills to the PX100's design or construction, but the combination of lightweight plastics, earcups mounted on ball sockets and a simple, adjustable metal band makes for a solid-feeling, comfortable set of cans. You can feel the pressure from the foam pads on your ears after a while, but this eases off a little with more use. The Sennheisers are certainly a lot easier on the outer ear than either the iGrados or the Audio-Technica ATH-ES3s. The cable, too, has a slightly higher quality feel, and while I'd normally worry a little about a plug that sticks out so far and so perpendicularly from the headphone socket, the flexible plastic cover does a lot to cushion any strain caused by sudden knocks or movements. The PX100s feel built to last.
As with the Porta Pros, sonic performance is impressive given the price. You can't expect the PX100s to compete with Sennheiser's full-sized, audiophile ‘phones, but the company has bought some of its tricks down to the portable range, borrowing elements of the open-backed design from the more pricey HD-414s and using some special damping techniques to keep the bass tight. The result is a pair of portable 'phones that do a fine job of replicating the sort of clean, crisp sound we expect from Sennheiser. Of all the sets on test, the PX100s offer the widest, most open soundstage, making tracks from Radiohead's In Rainbows album sound rich and atmospheric, and bringing out the intimate, acoustic feel of Alison Krauss's Lonely Cuts Both Ways LP. On pop tracks, like Justin Timberlake's What Goes Around, the PX100s put out a superb performance; the bass isn't as powerful and the overall tone isn't as warm as with the Koss Porta Pros, but an extra dose of clarity in the mid-range and high-end makes it easier to hear all the dense layers of the track.
On more bass heavy dance, hip-hop or electronic tracks the gutsy low-end of the Koss 'phones wins the day, and the same is true to a certain extent with heavy rock. All the same, what you lose in power you gain a little in detail, and the PX100s are probably the stronger 'phones for classical music. No headphone at this price point is going to cope with the full-scale onslaught of prime Wagner, but the opening sections of Das Rheingold still shine, and the golden string arrangements of Fantasia on a Theme by Thomas Tallis have a bit more air to breathe. Overall, the tone isn't as warm and loveable as that of the Porta Pros, but its natural and well-balanced. There's just something really pleasing about the way the Sennheisers put their sound together.
It's easy to see why so many people like the PX100s: they're a fine pair of headphones for the price. There is some sound leakage, but nowhere near the amount you'll find spilling from the iGrados or - to a much lesser extent - the Koss Porta Pros. If you don't like the ergonomics of the iGrados or the retro vibe of the Porta Pros- or if you're just willing to trade some bass and warmth for a very clean sound- then these make an excellent alternative.
A practical set of portable 'phones with a strong, clean, distinctively Sennheiser sound. Warmly recommended.