Here is an early edit of my HD 800 review which I have since expanded (thanks to the many commentors on the Playback version) that may capture the spirit of these headphones better than my version for publication in Playback:
Sennheiser HD 800 Headphones
Sennheiser is a bit like its German compatriots BMW and Mercedes-Benz. Sennheiser doesn’t produce the largest number of headphones or the most exotic designs, but the headphones it makes consistently start with a strong engineering foundation. When such a company ventures into the top level of headphone pricing (in this case $1399), it draws attention.
Sennheiser’s attack on the “best headphones possible” category is called the HD 800. That bland nomenclature belies the effort Sennheiser has put into the design of the HD 800. This isn’t just a slightly better HD 650 (their previous top of the line and a reference for many reviewers). No, the HD 800 is a new concept of how a headphone should work.
With the HD 800, Sennheiser reexamined the way it makes headphones. The first fundamental change was shifting to a much larger driver in each earcup. A larger driver makes it possible to deliver low bass with less distortion. But Sennheiser’s design is aimed at reducing distortion across the frequency spectrum, quoted as 14hz – 44khz (-3dB) or 6hz – 51khz (-10dB).
The second major innovation is the orientation of the drivers vis-à-vis your ears. Since your ears detect the sense of space through timing differences as sound waves strike your ear from the front, Sennheiser has angled the HD 800 drivers to enhance the sense of space that the headphones provide.
Sennheiser has also paid attention to comfort by using special ear pad materials and by employing new light but very hard plastics. All in all this is an aggressive attempt to deliver the best.
Consider this headphone if: you like a smooth, neutral sound that is clear but not aggressive. These will be a good choice if you have previously owned high-end Sennheiser’s and like them but wish for more extension at the frequency extremes.
I’m sure Sennheiser worked overtime to try to remove sonic character (as in, discernible colorations) from the HD 800s. Overall, the HD 800s have a generally neutral frequency balance. My listening revealed excellent deep bass and just enough mid-bass warmth to not feel noticeably deprived. Similarly, high frequencies are there in proper balance to the midrange. They are also clear in the way that comes from being low distortion rather than tweaked to fake your ear into thinking it is hearing true clarity. So we're talking about excellence.
I would say that the HD 800s are more natural and less analytical than some top ‘phones. This is good thing, especially when combined with the excellent treble performance on offer here.
This brings us to the question of whether the HD 800’s spatial engineering helps with the sense of soundstaging that is often a problem with headphones (a Sennheiser claim). I think they offer significantly more of the sense that instruments are being played in real space than other headphones, and that is an important advantage.
In summary, most headphones are pretty obviously flawed, if we’re honest. With the HD 800, Sennheiser has gone a long way to reduce those flaws, which makes this a very special pair of headphones.
Because the flaws in the HD 800 are in fact quite small, my colleague Alan Sircom was enthralled with the HD 800s when he reviewed them in our sister magazine from the UK, Hi-Fi Plus. He compared them with $25,000 loudspeakers to give you a sense of how much he loved them. With the right amplification, I get to the level of really, really liking the HD 800s. The HD 800s are so good that I could easily live with them over the long haul.
“Cheek to Cheek”, the opening track on Eva Cassidy’s fantastic Live at Blues Alley [Blix Street], tells you a lot about the HD 800s. First off, all the instruments from string bass to cymbals are well represented and in appropriate balance (a lot of headphones fail this test). Second, Eva’s voice via amplification has a very slight shrillness to it, which the HD800’s faithfully reproduce. That’s good in this case, because experience with this disc says that some shrillness is inherent to the recording. Headphones that soften the edges of the singer’s voice too much will typically sound foggy and drab on most material. But conversely, ‘phones that sharpen Eva’s voice too much and are likely to be unlistenable on the many bad recordings we get these days. Happily, the HD800’s find that “just right” balance point in the middle.
No two heads are alike, so your mileage may vary. I like circumaural headphones, and within this genre I thought the Sennheiser HD 800s were quite comfortable for long periods. The special alcantara material on the pads is very nice. The pressure is a little high, but the pads are so big this is well distributed.
A truly excellent headphone, the HD 800 will appeal to those who want a smooth and balanced sound with ample but not punishing clarity.
The gist of the review is that the HD 800s are superlative headphones that have specific and identifiable characteristics (which will make them ideal for some and not for others). This section is intended to give you an idea of the character of the HD 800s as an aid to understanding whether their particular nature (assets and deficiencies) is ideal for you.
All transducers have colorations (distortions). The HD 800s seem primarily to have subtractive colorations (de-emphasizing certain frequency bands, for example). This, I believe, is a key to understanding the HD 800s. Subtractive distortions have the virtue of calling less attention to themselves; and because the HD 800 has small subtractions the result is a very natural sound. The overall presentation of the HD 800s sounds rather like live music when compared with much of the reproduced sound we hear because we are so accustomed to additive colorations and distortions that call attention to the fact that the sound is reproduced not real. When you remove those additive distortions, you relax and feel things are more natural.
The price of the subtractive approach that Sennheiser has used is a certain loss of vividness. Vivid is an English word that simply means lifelike, clear, fresh, striking, intense; that's what I mean. Vividness is a holistic sense that the music is dynamic, clear and full of life. Live music is vivid. I use the term because some qualities don't reduce easily to a single analytical variable.
The HD 800s, at least with the amps I used initially (primarily the Luxman P200 and PS Audio GCHA), are not the most realistically vivid headphones you will find. For example, with the HD 800s you don’t initially get the sense of being directly coupled to the microphones that you do with some other top-of-the-line ‘phones. You could say that transparency isn’t as high as it might be, though it is pretty high relative to a lot of reproduced sound. But vividness is more than transparency.
I have since tried the prototype Woo Audio WA 22 amp (which is tube rather than solid state and has variable output impedance). The WA 22 takes the sense of vividness up a notch, mostly by making the midrange contrast level higher, while introducing minimal if any deleterious side effects. The mostly subtractive errors noted above are still there, but they are diminished in the overall presentation.
If you are still confused by this notion of the HD 800s being very natural sounding while sacrificing a little vividness, see my review of the Denon AH-D5000s for the opposite approach.
As for more specific characteristics, the bass of the HD 800s is also slightly soft. You don't hear the air of plucked bass or the punch of kick drum to the degree that you would with live music. I can imagine certain listeners wanting a little more bass to make up for the inevitable lack of the visceral impact you get with live music but can’t get with headphones.
The bass balance is on the light side in the mid-bass, though this is a small deviation. Hence the comment that there is enough warmth (in the mid-bass) to not feel deprived. This might normally signal a roll-off, but in the case of the HD 800s, that isn't the case; their deep bass is pretty solid.
The HD 800s seem to have a small dip in the upper midrange, which makes them slightly soft dynamically. I'd say the treble of the HD 800s is very slightly warmer than is perfectly neutral. Despite that, on occasion, vocals can sound slightly "sharp" rather than completely pure (this may be the HD 800 revealing decoding errors, but I believe something else is going on as well).
This brings us to the question of whether the HD 800’s spatial engineering helps with the sense of soundstaging that is often a problem with headphones (a Sennheiser claim). Here is what Sennheiser says:
"Sound waves channeled to our ears at a realistic angle ensure a sound as natural as the one generated by correctly positioned loudspeaker systems. Thanks to an innovative design, the HD 800 meets this requirement."
I’d have to disagree. The performers don’t seem to be on stage in front of you much more than with traditional headphones or earbuds. And with a standard amplifier, you still lack the crossfeed of left sounds into your right ear (and vice versa) that is part of normal listening. Don’t get me wrong, the HD 800s are no worse in these matters than other phones. But with the HD 800s those instruments in real space are positioned left and right of your ears, so the soundstage isn't like live music (with its positioning of performers in front of you, spread left to right). Just like other headphones, the HD 800s don’t image like speakers or live performers. That said, see the listening evaluation above for discussion of the excellent sense of space around instruments that HD 800s do create.
To repeat, the intent of this section is to describe the nature and limitations of the HD 800s. This critique discusses small deficiencies that should be measured against the overall excellence of the HD 800s. If one assumes that a headphone should be either a) nearly perfect or b) hands-down better than all other headphones to be worth $1399, then the HD 800s are not worth the money. Personally, I make neither of those assumptions, and consider the HD 800s to be an excellent value. But it is your money, so you have to decide.
As I mentioned in the article, I primarily used the Luxman P200 (which works well with many 'phones and was my favorite for the HD800s until the Woo WA22 arrived) and PS Audio GCHA headphone amps. I also used the Head Direct EF1 and Benchmark DAC1 Pre. Sources were the Esoteric DV-60 (in PCM>DSD mode or just DSD for SACD), Lector CDP-7 (and Benchmark DAC Pre D/A when that amp was used).
I would agree that amps matter with the HD 800s (and many other headphones). So do D/A converters (at least a big a factor as amps in the high frequencies). One thing that indicates is that the HD 800s are neutral enough to be quite revealing of small differences.
Most of the character I describe held up across the amps that I did use, with the exception of my point about vividness. But there could be a consistent interaction with these amps and the HD 800s that led me to believe I was describing the headphones when in fact I was describing a characteristic of these amps.
The comments above primarily try to describe the sound of the HD 800s relative to the sound of live music. The idea is that live music is a known thing to which all readers can relate. While relative performance between products can be helpful if you are interested in those two products, it isn't as helpful otherwise (because you generally don't know of or care about the reference). We try to do both kinds of comparisons (to live music and other products), but we use the live music reference as a starting point because it is more universal and more meaningful.
In summary, our reference (in Playback, AVGuide, HiFi+ and TAS audio reviews) is "the absolute sound". The absolute sound refers to the sound of unamplfied music played in a real acoustic space. The primary reference we have for judging the quality of equipment we review is the sound of live music, that is, the absolute sound. That because we need a reference (a measure) to judge things, and this reference needs to be known and stable (a guitar is always a guitar, so we can use it as a reference for communication now and in 5 years).
Harry Pearson, who came up with this idea, wanted to start with the end in mind. He claimed that we want music reproduction systems to come as close as possible to re-creating the sense of the live musical event. Since instruments in acoustic spaces, particularly unamplified instruments, have defined (and importantly for the reviewer, learnable) sounds they form the fundamental reference for determining if components are doing their job. This approach isn't without its difficulties, but most if not all other approaches have even more problems because they lack a clear and/or meaningful reference.
The purpose of the reference to live music is to explain where/how a piece of equipment is flawed or accurate and to articulate the magnitude of those flaws relative to a meaningful standard. We aren't judging the music, we are judging the ability of the equipment (and recording of necessity) to create a virtual reality facsimile of the music (the standard). Ideally, we would add, then, a comparison of these flaws and accuracies between two pieces of equipment.
Perhaps it is obvious from the above, but one really can't simply compare pieces of equipment. For example, if I say that headphone X has more mid-bass than headphone Y, it isn't useful because you don't know if headphone Y is deficient, accurate, or overpowering in the midbass relative to the sound of live music (unless you own headphone Y). I think it is safe to say the comparison with live music, while valid, isn't perfectly useful either because you want to know if a given product is the best you can get for your money.
I do want to say that I think the HD 800 is a substantial step ahead of the Sennheiser HD 650s. The HD 800 high frequencies are lower in distortion and better balanced. The low frequencies go deeper and the bass overall is more articulate. Whether these noticeable improvements are worth the extra cash is, of course, something for you to decide. The 800s don't sound radically different than the 650s, so they are worth the step up only if you like the 650s but would love to address a few issues with extension, transparency and treble balance.
The bass overall is more articulate on the 800s. This is also a small difference. There is a greater difference in the high frequencies between the HD 800s and the HD 650s. First, the HD 800s simply seem brighter. Since I'd say the 650s are on the dark side that isn't a bad thing, though there is room in the world for preferences (especially since so many popular recordings seem to be mixed on the hot side). What I don't think is arguable is that sometimes the 800s reveal an instrument where you can't really hear the instrument completely on the 650s. For example, on Annie Lennox' version of Ladies of the Canyon there is a cymbal in the background. On the 650s you might think it is a rim shot, but the 800s make it clear that it is a cymbal. All of this suggests to me that the 800s have flatter HF response.
For other headphones that are worth comparing to the HD 800s. Here are writeups of a few worthy competitors:
Ultrasone Edition 8 (First Listen with comparison to the HD 800s)
Denon AH-D5000 (Playback Review) -- these are very close relatives of the AH-D7000 (which I haven't heard, but understand are debatably better/worse)