Headphone Reviews

I do quite a bit of headphone listening during the day, making use of their convenience to shut out the office hubbub while I get down to serious copy editing. The system I use is modest—a pair of no-longer-available Sennheiser HD420SLs driven by an Advent 300 receiver I bought for $75, with CD source provided by a Denon DCD-1500 II—but I get quite a bit of musical satisfaction from it.

It was with great interest, therefore, that I read Part I of Bill Sommerwerck's monster headphone survey in the March 1991 issue, as well as Gary A. Galo's report on Joseph Grado's HP 1s elsewhere in this issue. Perhaps it behooves me to try some of these high-performance cans, thought I. Accordingly, I asked AKG to loan me another pair of their K-1000s (footnote 1), while GAG sent along the Grados he'd written about. I also borrowed a pair of the Stax Lambda Pro "Ear Speakers," as well as a Stax ED-1 diffuse-field equalizer. The Lambdas were driven by their SRM-1/Mk.II direct-drive, class-A, solid-state amplifier, using a Meridian 208 CD player as source, while both sets of dynamic 'phones were driven by the Advent receiver, by my home-brew dedicated class-A headphone amplifier, and by the pair of 25W VTL Tiny Triode tube amplifiers reviewed last month by Corey Greenberg. (These were fitted with a pair of Electronic Visionary Systems Ultimate Attenuators to provide volume control and to match the dynamic headphone level to that of the Stax.) My listening comments are an amalgam of the notes taken with all three amplifiers.

As well as using each pair of headphones for my daily music supply, I did some paired comparisons, matching levels by ear using the 1kHz warble tone on the Stereophile Test CD. First, the $1200 Stax Lambdas: I've used these electrostatics on most of the recording projects I've been involved in over the last few years, finding their clean low frequencies and superb retrieval of midrange detail essential to getting an optimum recorded balance. It could never be said that these were dull-sounding cans, however, and as well as an elevated mid-treble region, which somewhat accentuates tape hiss, their sound can sometimes become a bit steely; some audiophiles attribute this to the solid-state amplifier. Certainly when the amplifier is first switched on, the sound is objectionably hard; it takes at least 30 minutes to warm up. Nevertheless, the ease of the Lambdas' sound, coupled with their spacious presentation of recorded acoustics and a comfortable fit on the head, make for a lot of long-term listening pleasure.

Turning immediately to the beautifully made, $595 Grados after the Lambdas makes the dynamic cans sound shut-in in the mid- and high-treble by comparison. "The upper octaves [are] somewhat laid-back," says GAG; I agree that the HP 1's tonal balance is warmer, darker than the Stax. After comparing the two headphones on a number of different kinds of music, however, I found their overall smoothness became quite addictive. Voices, in particular, were reproduced with a seamless, natural quality. Despite the electrostatic 'phones' reputation for great bass, I actually found the Grados' low frequencies to be both cleaner and subjectively more powerful. LF pitch definition, too, was a little better with the dynamic 'phones. The Stax ED-1 equalizer rendered the Grados less warm, more natural-sounding, though there was then perhaps rather more grain to the sound.

Judging soundstaging with headphones is a little awkward, due to the fact that with conventional recordings, all the instruments are inside your head, hung on a line stretched between your ears. Binaural recordings, however, made with a dummy-head microphone, should produce out-of-the-head imaging with good headphones. To judge soundstaging I therefore used a number of my own binaural recordings as well as some CDs supplied by John Sunier of The Binaural Source (footnote 2).

The Grados didn't throw quite as wide a stage as the Staxes, though both were still excellent. Neither gave me an image to the front of my head with central sources, though this is something I have never found a pair of cans to do, even with the Stax diffuse-field equalizer in the chain. (I understand that this has something to do with the fact that the headphones have to have the exact response of the listener's pinna for this to happen, and that this is something that can only be approximated given that it is different for everyone.) Instead, frontal sources tend to move in an arch over my head.

All in all, while I wouldn't go quite as far as GAG does in recommending the Grado HP 1s for location monitoring, as their rather laid-back high frequencies might well cover up problems that would need to be heard—the tape squashing and dropouts on J. Gordon Holt's 1961 Dubois track on the Stereophile Test CD are much less audible on the Grados than they are via the Stax Lambdas, for example—I agree absolutely with him that they are excellent value for money, offering a superbly smooth, tonally accurate presentation, with extended lows. A winner, in my humble opinion, particularly given that a version without the polarity switches costs $100 less. And the combination with the $1200/pair VTL Tiny Triodes gave many happy hours of music—I would be intrigued to hear how the Stax SR-Lambda Signature, which includes a tube amp in its $2000 price and is the best-sounding headphone BS has heard, compares with this combination.

AKG's $895 K-1000s operate on a principle very different from the other headphones in that they offer a basically flat free-space response rather than one intended to duplicate the effect of the outer ear. The earpieces are therefore hinged to allow the listener to arrange for the sound to strike his or her ears from the correct, forward direction, allowing the pinnae to operate correctly. I swung out the drive-units to about a 30° angle, which seemed to give the best subjective balance between accuracy of midrange reproduction and the open, airy sound they then produced.

In his March review, BS was bothered by a nasal coloration that he felt to interfere with the K-1000's basically good sound quality. In my auditioning, I found that this nasality only developed to a significant degree when the K-1000's drive-units were not level with my ear canals. If you wear glasses and find that the headphone pads interfere with the earpieces, the '1000s are too low on your head and will sound nasal. You therefore need to move them up a little (footnote 3), something that you may or may not find comfortable depending on the exact shape of your head. (My wife, for example, who wears glasses, agreed with BS that it was hard to get the K-1000s to sit right.) But with the headphones correctly sited, the AKGs had a big, open sound that was extremely enjoyable. There was a freedom from sonic strain that actually proved a liability: I tended to play the music far too loud for long-term aural safety! (Other Stereophile staffers would venture into my office to see who was playing the music so loud!) Bass reproduction was surprisingly powerful, given the K-1000's unbaffled construction. Though the full weight of the pedal pipes in Jean Guillou's Pictures at an Exhibition and Petrouchka transcriptions (Dorian DOR-90117) was not apparent, they still sounded appropriately rich. Recorded bass guitar, too, had a good degree of transient "slam."

By comparison with the Stax Lambda Pros, the electrostatics could be heard to have more extended low frequencies, with an overall warmer midrange balance that emphasized the AKGs' residual nasality. Interestingly—and perhaps justifying the AKGs' design principle—the Staxes used with the ED-1 equalizer sounded similar to the AKGs used without, though the nod still has to go to the Lambdas for absolute midrange neutrality. (In this respect the Grados were better still.)

I found the open quality to the K-1000's presentation made the conventional headphones sound very closed-in by comparison. Via the AKGs, the Günther, Mike, and Sabine exchanges (footnote 4) on the AudioStax binaural CD were spatially the most natural-sounding of the four headphones mentioned in this follow-up: you not only heard, most convincingly, the presence of the open window to the left of the drier studio ambience, but also the external traffic noise being reflected within the studio itself. However, the voices still moved in an arch over, rather than in front of, my head.

It's in comparison with the significantly less expensive Grado HP 1s that the AKGs come under severe competition. While the American cans don't equal the Austrian cans' soundstage presentation, they have better-defined, more extended low frequencies and a more neutral midrange. In particular, the sound of the ringing telephone on the binaural CD is less resonant, with less mid-treble emphasis. But again, the AKGs sound so much more "open," something that using the Grados with the ED-1 diffuse-field equalizer doesn't compensate for.

I guess that those seriously interested in headphone listening should audition the Staxes, the Grados, and the AKGs to hear which best suits their own needs and tastes. I could certainly live happily with any of these high-performance headphones; each has its own peculiar combination of strengths and weaknesses. I can just imagine the ultimate 'phone: the midrange liquidity, bass slam, and low-treble neutrality of the Grados coupled with the extreme HF extension, midrange transparency, retrieval of detail, and comfort of the Lambdas, to which has been added the AKG's superb spatial presentation.

Dream on, JA.

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Footnote 1: John Marks also reviewed the AKG-1000 in June 2014.

Footnote 2: Perhaps the most stunning binaural recording I've heard, in terms of out-of-the-head experience, is the Space-Sound CD (AX CD 91 101) from AudioStax. When Günther Theile opens a window in the studio, it's as though a window has been opened in your room, complete with traffic noise. The Binaural Source, Box 1727, Ross, CA 94957.

Footnote 3: I find it surprising that AKG did not build any vertical adjustment into the design.

Footnote 4: "Hello." "Hello Günther." "Hello Zabine, hello Mike, hello Zabine..."—immortal dialog, I'm sure you'll agree.