SennheiserHD 600 - Audiophile Hi-Res Open Back Dynamic Headphone

If you are reading this, chances are you’re stuck in the exact same predicament that many of us find ourselves in at some point, including myself recently. Despite reading hundreds of forum posts, analyzing dozens of squiggling graphs, and scouring in-depth reviews for that potential “ah-ha!” moment that would convince me one way or another, I still found myself going in endless circles deciding on what to get. I started with the HD6XX due to its ridiculously good price when on sale (got mine at $179). With how impressed I was with it on my xDuoo TA-66, I knew I also had to try the others. Naturally, nothing in audio ever seems good enough, and once again I succumbed to the curiosity of something that might be “better”. And now we’re here.The only real difference between the three as far as “what's included” are the cables. HD6XX has a 4.5ft terminated into 1/8th (with adapter), HD600 has a 9ft into a 1/8th (with adapter), and the HD660s2 has two 6ft into a 1/4th and 4.4. HD600’s cable is the thinnest and most flexible, but both the cable and connectors are quite a bit smaller and don’t seem as durable. Other than the extra cable the HD660s2 includes, it also comes wrapped in a microfiber bag instead of a plastic bag like the others (must be where all that extra cost comes in). Jokes aside, physically all headphones are essentially the same, aside from the earcup frames of the HD600 and HD660s2 being more flat and the HD6XX more rounded.A word on amplification and gear. I'm using the Topping DX5 as the DAC (with headphone out for comparing) and the xDuoo TA-66 OTL tube amp. In conjunction with the stock tubes, I’m also testing RCA 6AS7G and 6080 for the rear, and Gold Lion 12AX7 (with adapter) and Voskhod 6N2P-EV for the front. Some combinations I’ve definitely liked more than others, but the stock tubes are FINE! Having owned the HD600 and HD650 many times in the past and heard them on a variety of equipment, after hearing them on the TA-66 I can confidently say these Senn’s really DO need tubes to sound their best. And for $250, I simply cannot recommend the TA-66 enough. I do believe an OTL tube amp is essential for any of these headphones as the sound changes/gains are quite obvious. Match made in heaven.So the adventure began with the HD6XX and the TA-66. I was so overjoyed with this combo and quite honestly, I’ve never heard the HD6XX/HD650 sound this good! My favorite combo was the RCA 6080 and the Gold Lion 12AX7, both waking up the HD6XX and injecting it with more energy. However I was NOT a fan of the RCA 6AS7G as it made them sound really mushy and strained. With how much I was enjoying the HD6XX this time around, I knew I had to get the HD600 once more, having preferred it to the HD650 in the past. To my surprise, I didn’t necessarily like it more? While the slightly more neutral sound signature was nice for some things, the HD6XX had a more pleasing and likeable tone. The HD600 could sometimes sound a tad thin in comparison. Honestly, both were so close and kept trading blows to the point where I couldn’t choose between them. Thus, the tie breaker is price. HD6XX takes it.Next up, the HD660s2. Having never heard these (or the originals), I wasn’t sure what to expect. I went into it fully hoping that they would be a clear winner with their “extended bass” and other tweaks. I had to do a bit of mental gymnastics to get past the price in comparison to the others ($399 on sale), but I told myself that if they were the tiebreaker and I generally preferred them to the other two that I’d keep them despite representing the worst value of the three. Immediately upon first listen, I did NOT like them! What was this? Bloated bass, darker sound even to the HD6XX, a slightly wonky tone, and no noticeable technical improvement in any other area? I was beside myself. This is Sennheiser’s latest and greatest HD6** headphone? First thing that came to mind was the HD700 with Dekoni pads. Was not a fan of those either for the same reason, but at least those were more comfortable and had a larger soundstage. Bass is what you notice first and foremost, and it distracts you from the magic mids. All things considered, the bass isn’t great either. Don’t be fooled into thinking this is a HD600 or HD6XX with “deep bass”.Another way of putting this is to think of the HD600 on a scale as a “1”, representing its level of bass and treble, with each sequential number decreasing treble and increasing bass. The HD6XX slots in as a “2”, a little less treble, a little more bass. HD660s2 would then be a “4” as I think the difference from the HD600 to HD6XX is smaller than the HD6XX to HD660s2. The DT880 would probably be a “0”, and my preference is probably around 1.5 or 2. Honestly, after following up listening to the HD660s2 with the HD6XX, the HD6XX sounds like it should be the HD660s3, because it “fixes” the flaws with the HD660s2. I just don’t get it. HD6XX and HD600 are clearly sidegrades to each other, whereas the HD660s2 is a downgrade in my opinion.Focusing on just the HD600 and HD6XX, these are some of my favorite headphones of all time. The glorious midrange is still unmatched and I have yet to find a headphone with better tone or timbre. The only other headphone I can recall liking more overall is the HE1000 Stealth. Despite my preference for light bass (I use Magnepan LRS+ with no subs for example), I actually lean more toward the HD6XX than the HD600 which surprised me. I think the HD6XX synergies with tubes a bit more and the sound seems just a little smoother, more cohesive, and more weighty. Both are just incredible headphones, but the HD6XX is unequivocally a no-brainer because of its price. On solid state amps, I find this series can be too mellow or restrained, but tubes really capitalize on their strengths and really are the key to unlocking their full potential.Let’s recap real quick and see the current standing. So we have the HD6XX around $200, the HD600 around $300, and the HD660s2 around $400. The HD6XX and HD600 are too close to call making the extra $100ish not seem like a good investment, yet here we have the HD660s2 which is unquestionably in 3rd place… yet they are DOUBLE the price of the HD6XX? Absolutely not. At the current pricing structure, quite frankly, the HD660s2 is a joke. Do I think the HD600 is a $300 headphone? Absolutely. How about the HD6XX? Yup. And the HD660s2? No way. I think they sound like a $200 headphone at best, but based on the HD6XX’s price, I personally would not pay more than $150 for them. By the same token, I also do not think the HD600 is worth $300+ considering the market disruptor HD6XX can be had for $179.That being said, I don’t think the HD660s2 is a bad headphone. In fact, I still did enjoy it once I got used to it. No doubt its flavor would appeal to some over the HD6XX or HD600 in direct comparison, but I emphasize “direct comparison”. Because at the end of the day, I can’t stress enough just how similar all three of these sound and to simply just buy whatever is cheapest or most available to you. Case in point, of the many hours I was comparing these three, I can’t tell you how many times I would literally forget which of them was on my head at that moment and would be blindsided when I pulled them off thinking it was one of the others. This really proved to me that once I started listening, the finer details and small tuning differences faded into obscurity and I was then just listening to a “Sennheiser” headphone.Wrapping up, the biggest discrepancy with this trio of headphones is undoubtedly price and value. So what do I recommend? If you don’t own any of these headphones, get the HD6XX when it's $179, a TA-66 for $249, have some fun rolling tubes, and enjoy the music! The tube swaps provided a bigger sound quality change than switching between these three headphones and for a whole lot cheaper! And if you already own any of these headphones and are tempted to purchase one of the others hoping for an upgrade, don’t bother… you only need one HD6** headphone. Famous last words: “you only need one”.

My road to the Sennheiser HD 600's has been a little long and filled with some interesting twists and turns that have, or so I hope, led me to a better understanding of what are a great set of headphones. Naturally it is very typical to wish to compare these to other headphones. After all, isn't that how we so often make purchasing decisions? We try differing products until we find the one which works best/right for our needs. So my review is going to work on two fronts: a review of the product itself, and a review against some competitors I have acquired in the last year in my quest to find headphones that are right for me. And hopefully for you.Regarding the HD600's themselves I have mostly nothing but excellent news to report. Personally, I like the way they look. The mottled black and blue coloring is different, but not garish in any way. The large and deep oval ear cups are precisely what one wants for an over-the-ear design. At 6'4" I'm certainly sporting a larger head than the average male and fortunately for me my entire ears fit comfortably inside the ear cups. My ears do not touch the protective cloth over the drivers, but the outer edge of my ear does touch at places around the inside of the ear cup. This is a minor annoyance and goes unnoticed some of the time. Those of you more average of height and head size will likely never have this issue. The ear cups themselves are very comfortable, seal well to my head and do not get hot even after a good number of hours of use. This also means the head clamping force is perfect for me; I never feel like my head is being squeezed. Everything about the headphones seems to indicate they are well-made, but I cannot help but feel the plastic seems a bit thin. Maybe cheap even. They do not creak and nothing flexes, but it's the only part which lets me down at all about the headphones.The included box, while awesome for storage, is clearly not oriented for travel. But I would argue these aren't portable headphones meant for the on-the-go user. They do not fold up. The ear cups do not turn to lay flat. And considering the amplification needed to properly drive these, using a typical portable music player (your cell phone, iPod, etc.) isn't ideal anyway.Now for what I consider to be the more important part of how I came to select the HD600: research and listening. Let's first be clear about something... audio equipment is not unlike some other equipment markets in that you often spend exponentially more money for an item just to gain minor, incremental increases in some important criteria. To you speaker X sounds better than speaker Y, all other things being equal. It's likely speaker X costs more. Most of the time it will cost more, but not all of the time. But how much more does it cost and how much more quality of sound are you receiving for that additional cost? It's almost always a matter of diminishing returns... loads more money for a bit firmer bass or slightly clearer treble. But this is the nirvana for which we seek in audio equipment.Over the last year I purchased two other sets of headphones: Grado 80e and Sennheiser Momentum. Clearly the Grado's at $100 are the least expensive with the Momentum jumping up markedly to $299, while the more recently acquired Sennheiser HD600 hit the $400 mark. Comparing my first two purchases, the 80e's and Momentum's, the differences were pretty straight-forwarded. To me the Grado's sounded brighter with good bass and sligthly harsh mids ("smeared" is the word which came to mind as I compared them in listening tests at home). The Mometum's sounded more laid back (not as bright) with great bass (that could be a bit smeared itself in the upper bass) and definitely superior mids (thinking men's voices here - became painfully obvious will using a live track from Morrissey between the two headphones). And so it was I came to find myself using each pair for different purposes.The Grado 80e's became my preferred can for classical music (a genre into which I am becoming more deeply involved of late) as I felt, for my personal preferences, the brighter qualities enhanced the instruments typical of classical music, while the bass was more than sufficient. But when I wanted to rock (or alternative as is more often the case) I broke out the Momentum's. The accentuated, but not overblown bass, was quite welcome and I noticed less the laid back nature of the treble, especially as I used them more and more.But with the also recent purchase of some better home audio equipment (Marantz CD6005 CD player and a SoundEngine D1 DAC/Headphone amp for my computer - listening to ALAC encoded tracks) I found myself thinking both the Momentum and 80e were somehow lacking. That I wasn't getting everything I could from my music via this better equipment.From all the research I had done previously I elected to spend the money and purchase the HD600. I don't think I have found a single bad review out there in the Internet sphere. A few have thought them a little warm or laid back. But most every review hits upon how, and especially for the money, the HD600s hit all the right notes (sorry). Having had them burned in for 30-hours the listening tests began. I had considered this purchase principally for classical music. I really didn't think I'd get more from them for rock/alternative than I was already getting from the Momentums and so it was the classical CDs came out and I plugged into the CD player. I also plugged in the Grados to the Marantz A/V receiver, direct mode engaged. Adjusting for volume as best I could (this is hardly scientific) I played a handful of very familiar tracks from very familiar CDs; swapping back and forth between the HD600s and Grado 80e.It too almost no time to hear the difference. I'll concede that it's sometimes difficult to put into words the differences heard, but I'll try. The first thing I noticed were the violins. When a number of them are playing notes together the Grado's sounded smeared compared to the HD600s. Not unlike a poorly created JPEG from a digital point-n-shoot versus a well-made JPEG from an original RAW processed via Adobe Lightroom. Details are are lost in the former, but the latter does a far superior job of keeping the detail even in the process of losing information. The HD600 left me feeling like I was actually sitting there in the room with the musicians. I'm not referring to placement of the instruments (the HD600 do a good job, but I've read reviews for other cans that do better), but simply how clear, precise, concise and live-sounding are the violins. Actually, it was true of all the stringed instruments. The resonance of the strings... their very clear nature... was a welcome and astonishing difference.Granted, the Grado's are one-quarter the cost and I shouldn't be surprised the HD600's sounded better. Markedly better. And I didn't have to listen long or hard to notice the differences. They are obvious; not subtle. That said, I can't say I was every displeased with the Grado's. It was only in comparison to the HD600's that it became possible to hear and understand the Grado's limitations.And like the stringed instruments, voices also became sharper, clearer, more focused. I had found what I was looking for regarding my classical music interests: a pair of headphones that while generally neutral (which some would consider to be 'flat' and flat has, I think, a negative connotation), are not at all boring or flat. I feel the music is more alive than ever in comparison to the Grado's.So... I also broke out some rock and alternative music (the recently remastered Led Zeppelin discs, some Nine Inch Nails and Pet Shop Boys) to see what the HD600's could do. Here I feared the Momentum would just kick butt thanks to the fuller bass, but I must say the HD600's continued to impress. All the good things they brought to mid and higher frequencies (clarity, precision) were still present, but, surprisingly, the bass was rock solid as well. I may hate myself for saying it, but I think the bass was a bit better. The upper-bass bloat in the Momentum's doesn't appear on the HD600's, which tends to make the lower-bass stand out more because they aren't overwhelmed by the enhanced upper-bass. I'd still say the Momentum's have more punch and who doesn't like that when listening to rock or alternative, but I could find myself readily using the HD600's just as often for The Smiths, The Cure, Skinny Puppy, etc. as I would the Momentum's.And here I think I have found a most excellent trio of headphones. Finding one perfect pair of headphones for all needs and opportunities is probably impossible. But I think I have accidentally stumbled upon a most excellent hat trick of cans that meet my various needs. I like to listen to music when I'm on the go; I have needs for portability. And while not truly the most portable of headphones, the Grado's for classical (and still quite reasonable for rock and alternative) and the Momentum's for rock and alternative (I confess I don't like them as much for classical as I do the Grado's for rock and alternative), AND the HD600's for more critical, at-home listening with audio equipment that has enough amplifier ooomph to properly push them.Add my name and voice to the long list of of folks who think, dollar for dollar, the Sennheiser HD600 are the best value in headphones out there.