Headphone Reviews

In February 1994, when I reviewed the pricey ($12,900 with amplifier) Sennheiser Orpheus headphone system—HE 90 headphones and HEV 90 D/A processor/amplifier—I commented that the company had a similar, but less expensive, alternative available: the HE 60 headphones combined with the HEV 70 amplifier. At the headphone end, the HE 60s aren't so different from the HE 90s furnished with the Orpheus system. Both are extremely lightweight and supremely comfortable—even for long listening sessions (I logged up to four hours without a break on the HE 60s). In fact, the less-expensive HE 60s are about 100gm—4 ounces—lighter than the HE 90s.

The HE 90s are built around earcups of thin beachwood; the earcups in the HE 60s are plastic. The headband in the more-expensive set is completely covered in leather; in the HE 60s, only the portion of the headset that comes in contact with the head is leather (this includes the earpad covers). The stationary electrodes in the HE 90s are of gold-plated crystal glass; in the HE 60s, they're a gold-plated resin polymer. The all-important diaphragms, however, are the same in both headphones: 1µm-thick gold-coated polymer foil. Both also use the same bias voltage and connecting cable.

The HEV 70 amplifier, on the other hand, is by its nature very different from the large, complex, tube amplifier in the Orpheus. The HEV 70 is a pure class-A MOSFET design. A single volume control (actually, a friction-ganged dual Alps potentiometer, which may be adjusted separately on each channel if desired) is located on the front panel, and a single unbalanced input is located on the rear. There's also a convenient set of output terminals (directly connected internally to the input terminals) that may be used if the HEV 70 is connected between the preamp and power amp. The amplifier is powered via an external power supply (one of those ubiquitous wall-warts).

Sound
The sound of the HE 60s/HEV 70 was strikingly similar to that of my recollection of the Orpheus (I no longer had the Orpheus on hand for direct comparison). The essentials were there: a clear, transparent sound with a slightly lean bass, some emphasis at the very top end, but a nonetheless pristinely clean presentation.

The most striking aspect of the Sennheiser's performance was its rendition of detail—so striking, in fact, that it just may be slightly "more real than real" in this respect. But it never sounded artificial—it simply provided an open window for information that's masked with even the very best loudspeakers. Everything was there—from every buzz of a guitar string to every inflection in a singer's voice. Hall ambience was also vividly clear. On "Zapateado," from Flamenco (Philips 422 069-2), Paco Romero's flying flamenco feet sent reverberations through what was clearly a good-sized studio; the echo slap-back from the walls was so clear I could almost calculate the size of the space. And the details of the footwork were so crisp and clear that a flamenco expert could probably figure out the steps from the sound alone. The slightly fuzzy spots of recordings over good loudspeakers turned out to be additional detail over the Sennheisers—detail so finely overlaid and integrated that it only made sense over a top-quality pair of headphones.

The resolution of the HE 60s/HEV 70 was never more evident than with Chesky's Jazz Sampler & Audiophile Test CD, Vol.3 (JD111), which contains excellent music tracks, and a variety of tests which demonstrate microphone placement, natural vs artificial space, natural vs artificial imaging, and natural vs compressed dynamics. While the differences ranged from subtle to quite evident, the Sennheisers were an ideal tool for hearing them.

The Sennheisers left nothing to be desired through the vital midrange. There was simply no coloration evident. Voices and solo instruments were vividly clear, the perspective just slightly laid-back rather than up-front and palpable. There was simply nothing to criticize in the Sennheiser's midband response.

The same is not completely true of the top end, however. The SE 60s/HEV 70 weren't "bright" in the proper meaning of the term—ie, a forwardness in the low-/mid-treble region. Neither did they sound hard or etched in any way. But the system was prominent at the very top of the treble range. Closely miked sibilants and hard transients with a lot of high-frequency overtones—high-hat, for example—often sounded zingy. To a certain extent, the Sennheiser was simply revealing what's on the recording; but with such behavior evident not only on standard commercial recordings but also on the offerings of top audiophile labels (Chesky, AudioQuest), the Sennheiser appeared to be contributing to the HF sparkle. I noted the same thing in the Orpheus, though the tube amplifier in that design sweetened the top end slightly more than did the HEV 70 MOSFET amp driving the HE 60s.

The top end of the HE 60s/HEV 70 was also more prominent than it might otherwise have been because of the system's cool, lean mid- and upper bass. There just wasn't quite enough natural body or weight to massed ensembles; voices, particularly male; and instruments with significant energy in this region—cellos, for example. While this does contribute significantly to the Sennheiser's open, transparent quality, ultimately it detracts from a natural spectral balance.

However, I have noted before that, because headphones are unable to replicate the tactile feel of loudspeakers, they sometimes compensate with an overly fat response. Sennheiser definitely has not gone down that road with the HE 60s/HEV 70. The bass was as tight as you're ever likely to hear from a transducer, though it still wasn't as viscerally exciting as that from good loudspeakers.

Nevertheless, apart from the upper-bass leanness noted above, the bottom end of the HE 60s/HEV 70 was extended, tight, and superbly defined, with no lack of weight at the extreme bottom of the range. The quality and quantity of deep bass was impeccable on the wide variety of tracks I often use to judge bass response: eg, the soundtrack of Patriot Games (RCA 07863-66051-2), for punch and definition; and Jean Guillou's organ transcription of Mussorgsky's Pictures at an Exhibition) (Dorian DOR-90117), for ultimate bass extension. Even recordings that have sounded too rich and loose at the bottom on other transducers—loudspeakers and headphones—were dramatically crisper with the Sennheisers. The kickdrum on Richard Thompson's Rumor & Sigh (Capitol C21S 95713 2), which can be too rich on many loudspeakers, was astonishingly tight.

Like all headphones, the Sennheiser HE 60s/HEV 70 presented a less-real soundstage than is possible with good, properly set-up loudspeakers. There's a test on the Chesky Jazz and Test CD in which David Chesky moves around the microphones, beating a tom-tom. With the Sennheisers, he clearly moved behind my head, around the side, then back through my head from ear to ear. The Orpheus did a better job (though a still far from perfect one) of getting the standard headphone image out into space and away from the inside of my head—where a headphone's "soundstage" is normally concentrated; but the HE 60s/HEV 70 nevertheless minimized that claustrophobic feel better than any competing headphones of which I'm aware. The inability of headphones to image clearly in front of a listener is nevertheless a physiological phenomenon—not a flaw of headphone design. Still, Sennheiser is doing something right here, even though the problem's complete solution does not appear to be in sight.

Conclusions
If you can't afford the Sennheiser Orpheus, the HE 60s/HEV 70 system is about as close as you'll get to the balance and overall sound character of the former's exceptional—but wildly priced—design. If you like your sound full-bodied and sweet, however, with nary a hint of high-frequency emphasis, you probably won't like this more affordable alternative. The HE 60s/HEV 70 are revealing and analytical, sometimes to a fault—the extreme top-end just might tell you more than you want to know about your recordings, adding, it seemed to me, a bit of its own commentary to the mix.

It's not really fair to directly compare the Sennheiser HE 60/HEV 70 combination with the Stax SR-Omega that I also review in this issue, however, without emphasizing their significant differences in price. The Sennheiser is best compared with the Stax SR-Lambda Signature T1. It's a close race. Both are a bit more vivid than life—the Sennheiser in the upper octave or two, the Stax in the low to mid treble. The Sennheiser sounds leaner, but with (perhaps because of this) a tighter, more detailed, extreme bottom end. Both are recommendable, though they sound different enough that a close audition of each is mandatory if you're shopping in this price range.