Select ComponentUltrasone Edition 8In the past decade, the ubiquity of the Apple iPod and other portable music players has dramatically increased the market for headphones. While the prices of these new offerings run the gamut from throwaway to four figures, most, in keeping with the emphasis on portability, tend to be earbuds or in-ear monitors -- full-size, high-quality headphones are still the province of audio engineers and a vocal minority of audiophiles. Still, headphone companies continue to release statement-level products to appeal to that niche market. One such example, the Edition 8s, from Germany's Ultrasone ($1499 USD), is the subject of this review.

Ultrasone has been designing and manufacturing headphones since the early 1990s. That makes them a relative newcomer in a product category in which most manufacturers have been in business since the early years of electronic recording. Unlike those other companies, Ultrasone makes nothing but headphones. Twenty years is more than enough time to have built a solid reputation, and Ultrasone has won numerous accolades and a devoted following of audio professionals.

All of Ultrasone's professional headphones share two characteristics: S-Logic and ULE shielding. In a natural listening environment, sounds first strike the outer ear and are then directed into the ear canal. Ultrasone's S-Logic natural surround technology uses decentralized driver location to direct sounds at the outer ear. This approach is more akin to listening to loudspeakers, and greatly improves spatial perception when listening through headphones. Another benefit of S-Logic is that, by using the natural amplification of the ear's outer structure, or pinna, the required sound-pressure level produced by the driver can be reduced by 3-4dB and still result in the same perceived loudness.

This reduction in sound-pressure level is safer for your hearing over the long term, and that's not the only way Ultrasone demonstrates its concern for those who spend many hours each day using their products (still, listening to any headphones at high volumes is not advisable). You may have read media reports about possible links between brain tumors and the radiation from cellular telephones. Although the frequencies involved are different, the drivers in headphones also produce electromagnetic waves very close to your head. Ultrasone's UltraLow-Emission (ULE) shielding blocks up to 90% of this radiation. Whether or not any health risks are ever proven, I see no need to unnecessarily irradiate my brain while listening to music. I don't know which of these two design characteristics might be responsible, but I have found Ultrasone headphones to cause less fatigue over long listening sessions than headphones from other manufacturers.

The Edition 8s aren't just at the top of Ultrasone's product line, they're in a wholly different class. Everything about the materials and construction defines them as a luxury product. The ear cups are crafted from ruthenium -- a highly scratch-resistant, silvery-white element in the platinum group. The ear pads and headband are covered with extremely supple, dark-gray Ethiopian sheepskin. In short, they're beautiful to behold and to handle. Nor is the Edition 8s' high-end cachet only about their appearance -- most aspects of the technical design are different from other Ultrasone headphones. The 40mm-diameter, titanium-plated tri-bass-tube driver is a special version of the one used in Ultrasone's Pro 900 and Pro 2900 models. Ultrasone uses titanium in its top-of-the-line offerings for its stiffness, which helps the diaphragm to better track signals. Drivers for the Edition headphones are impedance-matched to within 0.4%, to ensure excellent balance between channels. Finally, each pair of headphones is hand-assembled at Ultrasone's headquarters in Tutzing, Germany.

As is often the case with headphones, the Edition 8s' specifications are a little vague. The frequency response is stated as 6Hz-42kHz, but with no tolerance given. On the other hand, since a ruler-flat measured frequency response is not generally regarded as desirable for headphones, specifying the response to be within ±xdB wouldn't make much sense. The nominal impedance is 30 ohms, which should work fine with the vast majority of headphone amplifiers and portables. Sensitivity is given as 96dB, but without any indication of the input voltage -- I would assume 1V, but I've also seen headphones whose sensitivity is cited in terms of 1mW. I tried driving the Edition 8s with everything from a portable radio powered by a single AA battery, to my laptop's soundcard, to an iPod, to well-designed headphone amps, and always got plenty of volume.

Unboxing and setup

The packaging is a little underwhelming. Rather than the cherrywood case of the Edition 7s or the plastic and aluminum boxes of many other high-priced headphones, the Edition 8s come in a cardboard box. Although a beautiful madras goatskin bag is included for transport and storage, it only really provides protection from scuffing. The cables permanently attached to both ear cups are 1.2m long and terminated with a 1/8" gold-plated stereo plug, for convenient use with portable music sources. A 4m-long extension cable and a 1/8"-to-1/4" adapter are included. Almost all of my listening was done with an Ayre Acoustics C-5xeMP universal player feeding a Grace Design m902 headphone amplifier via a balanced connection. I also occasionally ran the coaxial digital output of my laptop into the Grace's own DAC.

Headphones rarely need "setting up." You just plug them in, put them on your head, and start listening. That wasn't quite the case with the Edition 8s. When I began listening to them, I found the bass entirely lacking -- quite a surprise for a pair of sealed cans. I decided to put them aside and let them burn in a while. After a few days, things seemed to have improved only slightly. Despite some immediately apparent strengths of the Edition 8s, I was beginning to think that I wasn't going to enjoy my time with them very much. Being accustomed to the Pro 2500s, I knew that achieving the very best spatial effect required paying some attention to positioning the headphones, so I started to move the Edition 8s around on my head and ears.

Voilà! Not only did the spatiality of the sound improve, there was immediately high-quality bass that plumbed the depths of recorded music. I had originally positioned the ear cups of the Edition 8 too high on my head. While the driver takes up a good portion of the ear cup, its sound is directed through a perforation at the bottom front, which apparently needs to be kept far away from the ear canal. I got the best results with the tops of the ear cups touching the tops of my ears and the headband tilted back a little. Once I found this sweet spot, it was no trouble to get used to putting them back in the same place. If you audition the Edition 8s for yourself, be sure to experiment with placement, or you may never hear what these headphones have to offer.

Comfort is, of course, a personal thing, but I found the Edition 8s to be comfortable even for very long listening sessions. At 260gm, they're relatively lightweight for full-sized 'phones, and they didn't make me feel as if my head were in a clamp. The ear cups are a bit on the small side, which may be a problem for those with larger ears. They also may be less than ideal for those who wear glasses -- the arms of the glasses frames will at least disrupt the circumaural seal, if not necessarily cause discomfort. The leather ear pads don't breathe the way cloth pads do, but somehow managed to be less sticky than the imitation leather used on some other headphones. Overall, my comfort level with the Edition 8s was somewhere between designs like the miserable supraaural Grados and the pampering Sennheiser HD 600s.

Ultrasone Edition 8


Sealed headphones have one distinct advantage over open-backed designs: they block outside noise. I would judge the isolation provided by the Edition 8s to be somewhere between 15 and 20dB, which is excellent. That level of isolation makes the 8s suitable for moderately loud environments, but even in a quiet listening room, the additional reduction in the ambient noise floor made perfectly audible the finest whisper of a performer's breath or the rustle of a turned page. Of course, a "black" background only enables details to be heard -- the headphones must still reproduce those details.

I was continually astonished by the Edition 8s' ability to deliver the subtlest sounds on a recording. It was less a matter of hearing things I'd never heard before -- though there was some of that -- than of more clearly hearing the sounds I knew were there. For example, I already appreciated both the musicianship and the recording quality on Wynton Marsalis's From Billie Holiday to Edith Piaf (CD, Rampart Street WME19457-2), but through the Edition 8s, each striking of the hi-hat in Ali Jackson's extended drum solos was rendered more closely to real life than I had ever heard before, or thought possible from the CD medium. It was just like being there, standing right next to the drum set. This album also has a marvelous recording of a plunger-muted trumpet, impeccably rendered by the Edition 8s. The Pittsburgh Symphony's recording of Berlioz's Symphonie Fantastique (SACD/CD, PentaTone PTC5186338) sounds great through many systems, but through the Edition 8s the chimes midway through Dream of a Witches' Sabbath took on a real shape -- from the initial stroke of the hammer through the swell and eventual decay -- and pizzicato passages were extraordinarily clean and precise.

Another aspect of the Edition 8's performance, closely related to detail but also to frequency extension, is their incredible reproduction of harmonic texture. When playing orchestral recordings, I reveled in the diverse instrumental timbres. It's not just that woodwinds sounded like woodwinds, but each individual flute and clarinet had its own character. I could also appreciate the varied tonal palette of a single instrument. With the Engegårdkvartetten's disc of string quartets by Haydn, Solberg, and Grieg (SACD/CD, 2L 53), the Edition 8s conveyed not only the balance between the sounds of the strings and the bodies of the instruments, but also a good measure of the sounds of the bows against the strings, and every variation of the pressure used. In the softer passages, the sound was lush and beautiful; in the forte passages, it had a little more bite. Sometimes I wondered if the headphones were displaying too much aggressiveness, or if they were just being honest. When a string instrument, particularly a violin, is played loudly, the sound is aggressive. That's especially the case when you're in close proximity to the instruments, as you are with this recording. Far too many components -- whether headphones, speakers, or electronics -- smooth over everything to make it sound beautiful. But fidelity is not euphony. The real beauty of music lies in its range of expression, and a system of true high fidelity will convey that entire range.

The issue of headphones' frequency response is not a simple one. No fewer than four different curves have been proposed by various researchers as the ideal headphone response, and relatively few designers and audio engineers believe that a flat measured response is optimal. Add the fact that Ultrasone headphones employ the uneven frequency amplification of the outer ear, and any objective measurement becomes useless, if not misleading. I can, however, compare the sound of the Edition 8s to that of speakers that I know to have a flat frequency response. I would judge the headphones to have a slight boost in the mid-treble -- for me, that means somewhere in the neighborhood of 8-12kHz. This would account for some of the abundance of detail that I heard, though most of it was simply due to the driver accurately tracking the input signal. The very highest frequencies were present and accounted for, but not emphasized. In fact, the ultrahighs were so refined that at first I was not quite cognizant of them -- but when I switched back to headphones with less extension, I sorely missed them. I've come to expect a boosted bass and midbass from sealed designs, but that's not what I heard from the Edition 8s. The bass was deep and solid, but not overemphasized. Using test tones, I determined that the low end of the Edition 8s reached smoothly down to 20Hz, with only a small hump at around 100Hz -- instead of the large, broad hump frequently designed into headphones to give the impression of abundant bass without actually delivering it.

When playing music, both the depth and quality of the Edition 8s' bass were outstanding: They could reproduce the lowest rumbles of large bass drums and the pedal tones of pipe organs. Combining that bass extension with the incredible delineation of transients gave a remarkable coherence to the sound of timpani -- reproducing the stroke of the mallet against the head through to the fundamental of the pitch. The low end also exhibited great agility. In walking bass lines, notes had precise leading edges and decayed naturally, with no bloat or overhang, giving exceptional rhythmic drive. Kick drums in rock recordings were positively explosive. Since listening through headphones lacks the physicality of listening through speakers, many people prefer having a little extra bass and/or midbass weight to make up the difference. I haven't heard headphones that deliver more low bass than the Edition 8s, but many 'phones -- and many speakers, for that matter -- do have a slightly more prominent midbass. In direct comparison, the Edition 8s may therefore sound a touch lean. I spent a little time listening to them with my HeadRoom Total BitHead headphone amplifier, which fleshed out the midbass a little, but at the expense of the very deep bass and some loss of agility. Other headphone amplifiers may produce different results, based on their overall character.

I used a number of vocal recordings in a variety of styles to assess the Edition 8s' midrange performance. Sopranos and altos were beguiling, but my impression of male voices depended a bit on the recording. Tenors were always outstanding, but the reduced midbass energy meant that baritones didn't always display as much chestiness as I've heard through some other transducers. That was particularly the case in closely miked pop recordings, but in operatic recordings the singers seemed to better maintain their power and tone. Of course, it's impossible to determine which components are giving the most accurate sound -- it's not a matter of one being believable and others not -- or which best reflects the intentions of the performers and audio engineers. Just as each instrument was rendered with a distinct harmonic texture, each voice had its own character, whether smooth and lush, nasal, or gravelly. The Edition 8s' clarity and speed also made lyrics exceptionally intelligible.

Soundstaging is not often discussed in headphone reviews, but in the case of the Edition 8s it is warranted. Even with S-Logic, listening to headphones is not the same as listening to speakers, nor does it provide a sensation of surround sound -- unless you're listening to a binaural recording. It does, however, bring most of the sound decidedly out of your head. Most good headphones can depict the positions of instruments and voices from left to right, but very few can give any sense of depth. What is special about the Ultrasones is that they not only gave an impression of depth, they could retain some layering -- I could clearly hear instruments at differing distances from front to back. The closest performers seemed rather closer to me than through many other headphones, but the soundstage extended far back beyond them. In the case of naturally miked orchestral recordings, the brass section could be significantly behind the strings, and the percussion even farther back. In many cases, there was even some sense of the recording venue. My experience of live operatic recordings benefited greatly from my being able to hear the movements of singers onstage and their interactions with each other. The Edition 8s couldn't produce a holographic image in the way a pair of good minimonitors can, but they got far closer to it than most people would believe headphones can get.

Being professional models designed for use by audio engineers, the Edition 8s told me exactly what was on the recording, without any sugarcoating. While exploring the 8s' bass performance, I listened to "Sister Rosetta Goes Before Us," from Robert Plant and Alison Krauss's Raising Sand (CD, Rounder 11661-9075-2). I expect somewhat overblown bass from this track, and I got it. The Edition 8s drew my attention to the indistinctness of both the bass and whatever drum is used -- it sounds like someone stamping on a wet cardboard box. It also made plain some grain in the treble. I decided to download the 24-bit/96kHz version from, which brought greater definition to the bass and eliminated some of the digital grain, but left intact the slight roughness that I think T Bone Burnett and Mike Piersante had in mind when they chose their microphones. Even the hiss on the higher-resolution file -- is it the tubed microphone or the analog tape? -- had greater extension and sounded a little sweeter, which somehow made it less obvious. The purpose of a high-fidelity audio system is to make such distinctions apparent, but you may not always be happy with the result. When I was listening to Charles Munch and the Boston Symphony's recording of Saint-Saëns' Symphony No.3 (SACD/CD, RCA Living Stereo 82876-61387-2RE1), it was revealed as the strident, compressed mush that it is -- not all Living Stereo recordings are this bad, but many are. If you spend a lot of time listening to less-than-perfect recordings, particularly if they tend toward brightness, you may not enjoy them as much through the Edition 8s. Just be sure to put the blame where it belongs: on the recording.


Because the Edition 8s are obviously aimed at the dedicated headphone listener who might be moving up to them from another good set of cans, I compared them with my Ultrasone Pro 2500s ($399 when available, now replaced by the Pro 2900s at $599) as well as a pair of Sennheiser HD 600s ($519, but selling for much less online), a de facto standard among audiophile headphones. These are wide-bandwidth designs that aim for subjectively flat frequency response and a high degree of transparency. One significant difference between both of these 'phones and the Edition 8s is that the former are open-backed designs. Conventional wisdom holds that open designs have an airier sound and lighter, though often better controlled, bass. Yes, the Edition 8s could go far lower than either of the other pairs, but bass weight was subjectively less than with the Pro 2500s, and noticeably more than with the HD 600s. Bass control was no contest. The Edition 8s thoroughly trounced the other two, more clearly delineating the beginning of each note and avoiding overhang while still conveying a natural decay.

Airiness and detail, though often considered together, are two different things. The Pro 2500s are just as detailed as the HD 600s, but the Sennheisers have significantly more air around instruments and voices -- they just sound more open. The Edition 8s sounded less airy and open than either of the other two, but conveyed gobs more detail. In the Edition 8s' case, the details emerged from an inky-black background rather than seeming to hover in empty space. Actually, that wasn't always true. Backgrounds were inky-black when the recording had been made in a studio or some other acoustically dead space. With recordings made in real concert halls, however, the background sound of the ambient environment was always audible. The Edition 8s also sounded much faster, better following the leading edges of transients.

High frequencies were handled differently by each of the three designs. The HD 600s seem a bit reticent in the very top, robbing instruments and voices of a little of their harmonic texture, but are exceedingly smooth on the way to the top. The Pro 2500s have a little more energy in the highs without tending toward brightness. The Edition 8s conveyed just as much high-frequency information as do the Pro 2500s, but painted with more delicate brushstrokes. Either of the Ultrasone designs conveyed more of the timbres of instruments than did the Sennheisers.

With respect to soundstaging, the HD 600 is a little confusing. In some ways voices and instruments seem far away, but this perception is more of a tonal effect than a spatial one. Like with most headphones, the entire performances happening within the confines of your head. The two Ultrasone designs had a front-of-the-hall sound, the Pro 2500s being a few rows behind the Edition 8s. Either of them created something more akin to a soundstage than did the Sennheisers, which varied significantly from recording to recording. Although the Edition 8s produced the most upfront sound, they could, given the right recording, produce a soundscape that extended much farther back and conveyed a greater sense of overall volume. The Edition 8s were also more precise than the Pro 2500s in the placement of instruments within that space. Even mono recordings, which put the entire ensemble right in the front of the head, seemed to have better focus with the Edition 8s. The combination of isolation from ambient noise and an enveloping sonic vista led to a more immersive listening experience with the Edition 8s than I've had with any other headphones.

I can enjoy listening to any of these headphones, but for highest fidelity and ultimate resolution, I have to give the nod to the Edition 8s. That additional detail wasn't there for its own sake, but brought more life and excitement to recorded music. The only caveat is that such a discriminating design will inevitably expose weaknesses in recordings and upstream components. That means that, for overall musical enjoyment, they may not always be the best choice. Once you've heard them with a good recording, though, it will be very difficult to go back.


The Ultrasone Edition 8s combine the traditional advantages of a sealed design -- superb isolation and extraordinary bass extension -- with the flat frequency response and articulation of the best open designs. They deliver an astounding level of detail that makes the best recordings really shine. The vividness with which the Edition 8s render the textures of voices and instruments is intoxicating, and must really be heard first-hand. If you're an audio engineer or audiophile and want to hear absolutely everything that's on each recording -- after all, that's what high fidelity is about -- you need to audition these headphones. Their steep price will limit their appeal to only the most dedicated headphone listeners, but it may be possible to justify the expenditure on sonic grounds alone. When you also consider the quality of the materials and workmanship, $1499 doesn't seem quite so outrageous. Given the personal nature of listening to music, and especially of headphones, there will never be one design on which all can agree -- but Ultrasone's Edition 8 headphones clearly belong on that short list of contenders for World's Greatest Headphone.

. . . S. Andrea Sundaram 

Associated Equipment 

  • Headphones -- Ultrasone Pro 2500, Sennheiser HD 600
  • Headphone amplifier -- Grace Design m902 , HeadRoom Total BitHead
  • Digital source -- Ayre C-5xeMP, Apple iPod (5th generation)
  • Interconnects -- DH Labs Revelation

Ultrasone Edition 8 Headphones
Price: $1499 USD.
Warranty: Five years parts and labor.

Ultrasone AG
Bernrieder Strasse 17b
D-82327 Tutzing, Bavaria
Phone: +49 (0)8158-9078-0
Fax: +49 (0)8158-9078-50


US distributor:
Ultrasone Inc.
40960 California Oaks Rd.
Murietta, CA 92562
Phone: (951) 677-4600
Fax: (951) 677-8662