Sennheiser HD600 Over-Ear Open Dynamic Hi-Fi Professional Stereo Headphones (Black)

Granted, all this comes at a pretty hefty price for a headphone. But the lightweight HD600 represents one hefty value. It so far outshines other headphones in sound quality, build quality, and comfort that despite its price it's still a strong value.

Of course, with a headphone like this and a name like Sennheiser, it's the sound you're really after. With stand-alone loudspeakers, the goal is generally to provide balanced sound across as much of the audible sound spectrum as possible (roughly 20 to 20,000 Hz). High-frequency reproduction is easier than low, simply because low-frequency reproduction requires a speaker to move so much air. Speakers capable of rendering deep bass usually use large speaker cones--8 inches or more in diameter--to help move the necessary volume of air.

Headphones, of course, are restricted in the sizes of the drivers they can use. Being so much closer to your ears, the amount of air they need to move to convey bass frequencies is much smaller, but still a challenge for what are basically tiny speaker cones. And anyone who's listened to a lot of headphones can tell you, there's almost always a tradeoff in what a headphone driver is capable of. Some produce balanced overall sound with little in the way of bass; others aim for bass at the expense of natural-sounding midrange and coloration-free treble.

The Sennheiser HD600, we're here to tell you, manages--through its extremely high-grade parts and exquisite engineering--to bring home truly full-range sound with remarkable timbral balance. Rich, deep, effortless bass grounds the listening experience while the headphone's airy midrange and treble help render everything from acoustic bass to soprano saxophone and electric guitars with a haunting degree of realism.

The HD600 doesn't offer the lush midrange favored by tube-amplifier enthusiasts--tube fans may find the headphone somewhat bright and maybe even strident in tone. But the rest of us will revel in the expanse of crystalline detail and snare-snappy dynamics.

The exceptionally natural quality of the HD600's overall sound bears reiteration, since so many headphones with "fat" or even "slamming" bass response deliver the low-end goods with a degree of emphasis that, while pleasing to bass aficionados, grossly distorts the frequency balance, limiting the range of music and recordings that will sound good on those headphones.

How does Sennheiser do it? Through computer-optimized magnets--critical to driver operation--that minimize harmonic and intermodulation distortion, granting the HD600 its uncanny clarity and spaciousness. Furthermore, the headphone's advanced diaphragm design eliminates standing waves in the diaphragm material, preventing unwanted emphasis at otherwise resonant frequencies.

As good as this headphone is, however, we don't recommend it to those seeking a stellar headphone for portable use. While this unit is capable of amazing sound, its best performance requires more amplifier power than most portable devices can muster. The HD600 owes its strength in part to its large drivers, which just can't be moved as easily as those in smaller headphones.

Furthermore, the HD600's open-ear design means that sounds pass easily into and out of these headphones, which would in all likelihood prove irritating to you and to those around you in libraries, on buses, and even at the office. These are only our suggestions, however; the fact is your MP3s will probably never sound better than when you're playing them over this headset.

We'll just leave you with one last suggestion, then: if you're after the best-sounding, most comfortable audiophile headphones you can buy at anything resembling a real-world price, look no further than Sennheiser's HD600. --Michael Mikesell

Pros:

• Natural timbral balance
• Extremely detailed presentation
• Excellent bass extension
• Produces a spacious, wider-than-your-head soundstage
• Terrifically comfortable

Cons:

• Slightly bright treble for some tastes

Features of the HD600 include a sophisticated design, elegantly finished in black and gray with high-quality open metal-mesh earpiece covers for an extremely transparent sound. Computer-optimized magnet systems minimize harmonic and intermodulation distortion, while extremely lightweight aluminum voice coils ensure excellent transient response. Neodymium ferrous magnet systems ensure optimum sensitivity and an excellent dynamic response. The result is an exceptionally natural, spatial, and accurate sound.

The HD600 comes with a 3-meter detachable, dual-sided oxygen-free copper cable with very low handling noise, and a 0.125-inch stereo minijack plug with a 0.25-inch stereo jack plug adapter.

Sennheiser headphones come with a two-year warranty on parts and labor.