The Massdrop HD6XX is a hugely popular twist on the Sennheiser HD650 variant headphone and a partnership between Drop and Sennheiser. It is priced at $199.

Disclaimer: The Massdrop HD6XX sent to us is a sample in exchange for our honest opinion. We thank the team at Massdrop for giving us this opportunity.

To read more about Massdrop collaborations we have reviewed on Headfonics click here.

I’m not going to bore anyone with the detailed history of this headphone’s past, at least not beyond the fact that the original HD650 was first released way back in 2003.

Damn…do you know what I was doing in 2003?! I was salivating like a super nerd over true closure in my life and after the Lord of the Rings: Return of the King trailer was gifted to us, having girlfriend issues back in 11th grade in high school, debating how Finding Nemo would surely win the Oscar that year and also terrified over the idea that The Terminator himself somehow got elected in California.

Damn you, Sennheiser! Damn you for releasing this headphone in 2003 and not in 2002 when I actually needed it. I could have had a far less stressful and happier time in high school if I had been able to take my HD650 with me to use during study hall or lunch hour. My crippling depression and regrets are on you.

The King is still King

Let’s make no mistake. The HD650 still owns all the land in the sub $500 tier for open backs, despite a few competing threats to its 15 years or so reign after it was first released. In late-2016, Massdrop collaborated with Sennheiser to produce this HD650 variant, broke their website with pre-orders, and has since been unable to keep stock of the new model HD6XX. Rightly so. The only difference between the original HD650 and the Massdrop HD6XX is a new, deep blue paint job, a different box.

Also included, a shorter 3.5mm cable included instead of the god awful stock cables Sennheiser still stuffs into their boxes because they still have not figured out yet that people do in fact have this thing called “portable rigs”. These mystical, mythical things called “portable rigs” sound amazing now and that we’ve no real need for a 15ft, super thick ¼ giant adapter termination that requires an extra ¼ to 3.5mm adapter to be used on a tiny little 3.5mm output jack on your Astell and Kern, Cowon or whatever the hell other nice DAP you happened to solicit on Head Fi’s forums…

The Cable

Sweet Baby Jesus, someone finally listened. All I can say is thank you “insert name of the random person who insisted that the HD6XX come only with a 5ft long, 3.5mm terminated HD650 cable.”. Thank you for not forcing me to pay $150+ for a custom cable just so I can use it around the house and on the go. The cable is perfect for most of us who don’t care too much about cables. Nothing else needs to be said. It is just the right length for a human being…unless you are a mutant who is reading this in the post-apocalyptic, run-down world where headphones have become a currency and who could be over 10ft tall.

Musicality Incarnate – Tone

Ye Old’ HD650 has always been the poster child of Musicality: the less clinical and more fun-sounding headphone sound type. Without taking it too far into the boosted area, few headphones offered such a vivid heft to the overall sound signature as the HD650/6XX have. Truly, it took a decade and a half for another company entirely to actually make a proper upgrade to the HD650 that retained a similar sound signature and presentation, but that drastically improved quality across the board: The Focal Elear.

Musicality is hard to get right and it is a rare type of sound in the ‘High-End’ world of headphones. It seems the shift of expensive headphones these days has gone the way of surgical accuracy, forgetting that there are many listeners out there who prefer a thickness to the sound signature itself, some boosted bass and vivid treble. Of course, without going overboard…and that is where the HD6XX and HD650 shine.

The man or woman who tuned the HD650 should have received an award for adjusting literal, physical quantities of bass and treble in perhaps the yummiest manner on the market, especially so back in 2003 when pretty much nothing great also shared that sound signature. Hell, the HD650 was a vast departure from its more clinical little brother: The HD600.

I still see HD650’s being sold for $499 here and there on the Internet and nearer to $300 on the used market. I paid $299 for my used HD650 a few years ago and thought I got a good deal. Somehow, Massdrop was able to sell this HD6XX for $199 new. They’ve effectively destroyed the market for used HD650’s, but I suspect neither HD650 owners, nor Sennheiser will ever drop prices. You can’t question this, it is the law now: This Massdrop HD6XX is the best overall deal in the full-size headphone world. Price tiers are irrelevant. For $199?! You can’t beat this.


The lower regions of the HD6XX are neither impressively responsive nor absurdly clean when comparing it to the current era headphone titans. Back when it was released, it was top tier. Today, though, many other sets have matched and even exceeded the response capabilities of the HD650. It is not the best you can get, but it is the most well rounded now for the $199 and under tier, I don’t think anyone can honestly state otherwise. You’ll need to seek out specialized headphones, or very new headphones to get on this level of quality, headphones like the Philips Fidelio series are good alternatives that also offer more physical quantity and equal clarity.

True, that the HD650 scales up in cleanliness with more power and higher quality amplifiers and USB DAC’s. Out of my Airist Audio Heron 5 ($2000 originally, but now only $999), the HD6XX sings with impressive smoothness.

I’ve not heard anything this smooth in the $500 and under open-back headphone world, nor have I ever used an open headphone that cheap that also scales up with better equipment to such a degree. But then again, this is no surprise to HD650 owners of the past, as we all are perfectly aware that the HD650 is legendary with regard to scalability factor: put more voltage and better quality into the fire, receive a better edge on your blade.

Not many other sets can sound that nice on a portable rig without any amplification, but then very noticeably improve beyond what you might have thought it would have with proper amplification and rig pairing behind it.


The HD6XX is a mellow sounding headphone, one that lacks harsh physical impact (dynamics) and that has a relaxed midrange. With that in mind, it is not presented as a V-shaped headphone, meaning more bass and treble than midrange, which causes a distant-feeling vocal experience. Thankfully, that is not the case here and the presentation of the midrange is in balance with the treble and bass in terms of quantities provided, but still “relaxed and not forward“. This is a great thing if you just want to kick back and chill out, grab a glass of wine or even take a walk when the weather is nice.

The tonality of the HD6XX is soft on the edges and not clinical, surgical or at all quick with decay factor. What I mean by that is that the headphone lingers on just a bit, especially so in the lower midrange to my ear. Some headphones simply sound fast, effortless or your pick of other “accurate” sounding terms used to describe a neutral sound signature. The HD6XX is not neutral. It is gently warm, boosted and vivid in heft to the entire spectrum, top to bottom. This lends credibility and enjoyment factor for those who don’t want to wince or feel the nasal tendency that very neutral headphones offer. If you like musical enjoyment over the accuracy, this is the headphone for you.

Treble- Veil! AH, RUN!

Nah. It really isn’t a problem. Boost your EQ a bit up top and you’ll be fine. I never understood this veil topic that much. I understand it from a technical standpoint, as the HD650 sounds less prone to hiss, static, and brightness by comparison to the HD600 (which is the neutral benchmark headphone in that price tier). But, this HD650 is all about the enjoyment on a musical level, so they made sure to tune it down a bit up top so you don’t ever shrug and blink in pain when that swing’n jazz cat smacks the high hat cymbal hard in the track.

If you want to experience that, grab the HD600, and enjoy your bleeding ear for the sake of accuracy if the track isn’t nicely recorded. If you want to experience a subdued, lesser quantity up top experience that is still present enough to swing a “meh” vote, then the HD650/6xx should be on your bucket list.

I can hear a quality difference between my $799 Cowon Plenue M portable player and when I use the Plenue M as a pure DAC and tack on my Airist Audio Heron 5 as an amplifier in the chain. So, there really is no doubt that the HD6XX scales up again here with the treble quality and with the home desktop rig, I don’t really notice much of a problem. Again, reviewers seem to forget this headphone is now $199, so the complaint about a veil at this price range seems unfair. Boost the treble a bit. It helps with that, it is why the Audio Gods made EQ for us. Use it. It is not a sin. You are using a musical headphone aimed for musicality and enjoyment, so why stick with the stock sound if you can alter it a bit to make things more to your enjoyment?

Sound Stage/Imaging

Sadly, the HD6XX does not image grandly. Is it poor in that regard? Certainly not. Just good seems more appropriate of a phrase used to describe sound staging experiences on this headphone. It doesn’t exist vividly deep, tall or wide, but has enough depth of field to enjoy for me. I understand the plight of many owners here with regard to the width and height factor feeling a bit constrained, but the depth of field and realism factor seems just good for the price, even still today.

No doubt, Philips bested Sennheiser here with their Fidelio lineup, so if you want much nicer staging properties, I’d opt for the X1 or the X2 instead. The headphone is also just god awful for gaming. Pinpoint accuracy is so vividly terrible here, that my ears cannot properly tell where an enemy may be hiding or running in CoD or your pick of any FPS game online. For casual, single-player gaming? Hell ya! Go for it, as the experience is yummy, soft and fatigue-free throughout. For pinpointing locations of sounds in the game void, this is a horrendous failure. Grab a used ATH AD700 instead if you are an FPS gamer in need of location spotting.

Our Verdict

Oh, come on! The HD6XX is a brand new HD650 for only $199. It probably has a better paint job as well that won’t decay in a few years time, as all HD650’s of old tend to. This is quite literally the best open-back headphone deal that exists and I hope it forces Sennheiser to wake up and go back to their roots. I’ve cried for years and felt supremely lonely in the fact that I am a musicality buff and personally prefer fun over accuracy in my headphones. It seems like the HiFi market shifted to mostly natural/neutral sound signatures and forgot about the classic, musical sounding headphones from yesteryear, the HD650 is the poster boy of that class of listeners.

The proof is in the pudding, as the demand for the HD6XX is exceeding what Massdrop can even produce and it feels like Sennheiser needs to revamp this headphone with an HD800 variant that sounds just like the HD650, but scaled in quality to the HD800 level. We, musicality lovers, are here to stay and there are much more than I thought that still are around. No, buyers like me do not personally want brutal, clinical and cold sounding products that relay the track as it was recorded.

Come on, Sennheiser. Release an HD799, a variant of the HD650 that did the fusion dance with the HD800 and created the undisputed Super Saiyan of musicality and massive sound stage. Until then, we HD6XX owners are just going to pester you until you do.

We all owe Massdrop a huge thank you for giving us a $199 HD650. Toss them an email saying thank you for dropping the price on this headphone and giving it an overhaul in the community. They deserve the gesture and years later, I enjoy this headphone just as much now as I did back then. Thank you, Massdrop. Thank you, Sennheiser for finally caving on the pricing and allowing it to be sold this cheap.

HD6XX Technical Specifications

  • Color: Midnight blue
  • Transducer principle: Open, dynamic
  • Frequency response: 10 Hz – 41 kHz
  • THD: < 0.05%
  • Nominal impedance: 300 ohm
  • Cable length: 6 ft (1.8 m)
  • Connector: ⅛ in (0.3 cm)
  • Weight without cable: 9.2 oz (260 g)
  • Made in Ireland


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24 Responses

  1. Josh

    Respectfully, with regard to the cable, my receiver (which is my primary dac/amp for headphone listening) is about 6ft away from my primary listening position across the room. I’ve been using Sony MDR-V6 headphones for many years now (with a 10ft cable) and the length is pretty much ideal for my listening needs while still giving enough slack for moving around. I’m not sure if it’s because it’s coiled or if it’s just me, but I also listen to my v6’s portably with my laptop or with my phone and a dongle DAC and I’ve never really had problems with having too much cable… I just shove what i don’t need in a pocket and it’s fine. I just ordered a set of 6xx’s from Drop and I’m actually considering finding an OEM hd 650 cable to replace it with because I’m not sure if the 6xx’s 5′ cable is long enough. Further, I’m about 6′ myself, and if I’m listening to my nice headphones, I don’t want them ripped off my head if I accidentally drop my phone/music player.

    • Michael


      Have you considered just a regular headphone extension cable? HD650 custom cable replacements are quite common thankfully. But, I would just opt for a simple male 3.5mm to female 3.5mm extension cable. So long as you aren’t buying a pure silver based extension cable, you will be fine. I prefer extension cables like this to avoid a ton of slack when I do listen portably.

      Looking on Amazon right now, I see a few 3 meter long HD650 replacement cables for $21-25USD.

      Either route you go, you will be fine. IMO, the HD650 is not cable sensitive. You don’t need to buy a super expensive cable for that.

  2. Gene

    I am listening to “Muddy Waters – Folk Singer” with my HD-6XX plugged to OTL LIttle Dot MK II headphone amplifier with Russian power tubes and Mullard UK tubes, FX Audio DAC-X6 as the DAC and audio source is Flac.

    Believe me, fellas, this is out of this world, It feels like I am right there in that concert back in 1963 (or 64). It is not just headphones, they are a Time machine when properly powered.


    • Jim

      I use my HD 6XX and HD 600 with a Little Dot MK2 Ver. 3 and it’s a great match.
      The level of detail and wonderful tone call into question the law of diminishing returns here, since I would have to spend thousands to significantly improve
      on this combo.

      Happy listening!

  3. Pete

    “Then grab the HD600 and enjoy your bleeding ear.”
    The HD600 is neither bright or piercing. The treble simply isn’t rolled off. What did you listen to it out of, an IPod Classic?

    • Michael

      Hi, Pete. Treble being rolled off was never stated in my comment with regard to the HD600. The opposite of that was stated. I said the HD600 is a more neutral headphone and, in turn, the one more prone to be closer to accurate with treble response vs the HD650. Where as, the HD650 is very colored and subdued by comparison.

      Roll off = reference to the point (frequency) where treble energy starts to diminish, or cease to exist above a certain frequency.

      The HD650 is rolled off. Because it is fairly subdued and much more exaggerating than the HD600. It will not sound as wince worthy, icy, or painful as the HD600 would on the same painfully recorded track. The HD600 is not nearly as rolled off. It is the more accurate in presentation, tone and physical dynamic impact of the two and will always be the more revealing of the two. The HD650 is much more musical and fun sounding set.

      The HD600 is the more accurate and revealing, which makes it the more painful of the two when listening to harsh and painful, wince worthy tracks. Hope that helps.


      • Tim

        Now, what we have here is a failure . . .

        Pete was very obviously saying that in regard to the treble or the frequencies that are generally considered to sound harsh when over emphasized, the difference between these two headphones, the 600s and the 650s, is that the 600s do not have the treble rolled off where the 650s do, and that, since the treble on the 600s is neither hyped nor rolled off, the 600s have neither exceptionally harsh nor exceptionally mellow high end, but rather the difference is that the 650s have been toned down a little, making them making them have a more mellow treble sound in comparison to the 600s. In essence, his opinion is that the 600s are not harsh unless you are listening on an iPod classic or some other inferior sounding or treble hyped device, and he therefor disagrees with your characterization of the 600s as being so harsh that they will make your ears bleed. I have no dog in this fight, but It does seem like you may have exaggerated just a little bit in your characterization of one of the better sets of studio cans as aural assault weapons. Undoubtedly this was done to add colorful humor and emphasis to your article to make it more enjoyable to read, and this is not an atypical style of comparative review writing. But this is all beside the point anyway.

        I’m sure nobody had bad intentions toward anybody here, but I’m also pretty sure that Pete did not appreciate a snarky lecture on basic audio principles and term definitions from somebody who felt the need to talk down to him but not the need to carefully read or consider what Pete had actually said in the first place, which would have lead to the conclusion that Pete had not in fact shown any lack of understanding or misuse of any audio terms or principles. Nobody likes being spoken down to, but we like it even less when we see others speaking down to people when they themselves are the ones in the wrong. That being said, simple apologies and admission of mistakes go a long way to lesson the poor impression that has been made to anyone. Especially now when so many people would simply argue to the death over any little thing just as long as they don’t have to admit being wrong. But I digress . . .

        hwat wea have ow-uh say-ulvz hea-uh,
        Izzuh fay-ull-yuh . . .
        tuh calm-eunuch-hate! 😒🤖🤨
        (If we must hate 😡each other for re-
        dickyouless🤪 reasons, surely we can at least do it ✔️ calmly😒)

        After much research, and many, many mistakes . . .

        . . . Wait, what was I gonna say? What was the question again? . . .

  4. Carlos


    I currently own a pair of HD598´s. I´m certainly attracted by the excellent 200$ price point of the HD6XX, but since I mostly use my 598´s for movies and I´ve read that the 650´s have a lower (albeit better?) soundstage I´m not sure if the upgrade is worthwile. I power them with a Creative Sound Blaster ZXR sound card from my HTPC that can drive 600 ohm headphones so that should not be a problem. Also for music listening I normally used some other closed cans as the 598s are too bass light in that regard. What´s your opinion about 598 vs 650 for movie watching? Thanks and best regards :)

    • Michael

      The 650 has always been my pick for movie and media usage. It is (subjectively) due to a soft appeal and lacking dynamic kick and slam factor. It is easier to listen to for long periods for me, it is also more coherent and focused in the midrange. The Hd650 is the more refined and elegant sounding, has a more relaxed midrange and treble. The HD598 is more lively and engaging, more forward feeling and has more treble energy. But, quality overall still remains superior with the HD650.

      Depends on your preference. If you like a more relaxed sound that is softer on your ear, the HD6xx is the wiser route.

    • 24bit

      The HD650 would be the one you’d want to use if you want a softer approach to everything, less dynamic impact and easier on the ear to listen to for prolonged periods of time. The Bass is slow and wooly, but not what I’d consider deep reaching. The Mids are relaxed and a bit distant, but so is the entire spectrum. Treble is sparkled and very easy to listen to, dense feeling and not potent. HD650 is dark sounding.

      The HD598 is more lively and engaging, the more forward feeling and has more treble energy too. The sound stage shape is different, the HD650 more balanced in depth, width and height. The HD598 a noticeably wider feeling to my ears. HD598 is brighter feeling.

      Depends on your preferences, mate. If you like soft, relaxed, dark sound, HD650 is the wiser route.



    I saw you also reviewed xrkAudio portable class A pocket amp.

    I finally was able to get in on the 6xx drop (just received them yesterday). This is my first foray into hifi and the setup I decided on was:

    Google pixel (UAPP) -> audioquest dragonfly red (bit perfect) –> xrk pocket amp (NHB) –> HD6xx

    I don’t have any comparison points so my question is: am I scaling the HD6xx appropriately or does my setup any shortcomings from your perspective?

    • 24bit

      Hi Brian. You’ll love that setup, if you enjoy the musical and soft appeal of the HD650 in general. The XRK accentuates that and keeps things musical, fun and lacking any fatiguing impact in terms of slam effect. You might even find that you don’t really need the Dragonfly in theory, as I found I didn’t need my Kitty DAC for my Samsung phone.

      I talk about this in my Kitty review from Speakertec, which is a USB dac for phones. My setup was: Samsung phone > Kitty > XRK > headphone

      and I found the XRK so nice, that I didn’t need the Dac connected to the phone. If you aren’t using a mojo level USB DAC output, I am not sure I really care too much about any DAC in the middle unless .DSD is in play and the phone needs the DAC to unlock it. I was just fine and happy with my phones 3.5mm direct to the XRK for usage with the HD6xx. But that’s entirely subjective. In terms of rig pairing, the HD6xx will pair very well with your setup, the Dragonfly in the middle is just a bonus I think.

      Don’t worry about scaling. The UBER XRK circuit is superior to Ray Samuels SR71B and even my older ALO audio International and RX MK3. Wouldn’t worry at all, mate. That XRK is a wolf in sheep’s clothing and there really are not too many other amps on the market that will do justice to the HD650 in terms of that soft appeal on tone, the musical flare in tone and also coming stock with a very nice bass response. Musical amps are hard to come by.

      • BRIAN LEM

        Thanks for the detailed response. I understand that the xrk uber builds on the already warm characteristics of the HD6xx. If I were using a chord mojo instead would I be hearing more distinction between musical notes or more clarity in the mids and treble?

        This is purely out of curiosity since I already have my setup and am more than happy with it with no intention to change. I find one of the more difficult aspects of getting into hifi is understanding the adjectives that seasoned audiophiles are able to relate to. Thanks for sharing the wisdom!

    • 24bit

      DT880 – Bass and sound stage are more well formed and interesting, more neutral and cold sounding, thinner sounding, harsher impact but more fun as well. If it is the 32ohm, it is much easier to drive. Audible bass response superiority, however there is little substance down there meaning it responds nice to very low Freq range in the low end, but quantity just isn’t there. Has much brighter treble, can be harsh at times.

      HD650 – Better midrange quality, tamed treble, less bass, much smoother sounding, more heft to the sound signature as a whole, harder to drive, colored tone but not too much. Nowhere near as cool sounding as the DT880. Scales up more with better sources/amps. Responds less than the DT880 in the bass area. Almost never harsh up top.

      The DT880 has contrasting traits compared to he HD650, so if you love the DT880, you’ll be getting a lot of the opposite in the HD650. This would all depend on your preference.

      • pyktures

        Thx (woah been a while now lol). So the 6XX and 650 are very close in sound?

      • 24bit

        Same everything, including the drivers. Only differences are the paint job and cable.

  6. GT Campbell

    I was one of the lucky few who managed to pick up a pair of these headphones the day they dropped on MassDrop. I agree that they are phenomenal, especially for the price! I finally retired my HD600s in favor of these when I plugged these in for the first time. I also really like the shorter cord, but there are times I’d love to have an additional foot or so of cord. If MassDrop does another drop of these I’ll probably pick up another pair.

    • 24bit

      Hell of a Collectors item as well, I predict. In a decade, users will want this variant and it will be highly sought after. At least, that is what my gut tells me. 15 years later, pricing on the used HD650 is still $225-300 depending on condition. Years from now, the $199 new HD6xx will NEVER achieve similar percentage loss. It is going to retain value or actually exceed the new cost, despite being used. Not a soul will sell the HD6xx for $199 used in about 10 years, so I think the market value will eventually exceed the list price of the HD6xx. I’m with you, I’ll pick another up as well if I can manage to battle off others when it gets dropped.

      *sharpens Katana*

      • Pakalini

        collectors… That’s why I always lose on Massdrop! :<

      • Jan

        The latest HD6xx drop was limited in quantity per person, and it lasted for a really long time, and they increased the available stock mid drop, so it wasn’t very easy to lose it at all, unless you waited until the last day to buy it.

  7. Dgr Rse

    I wasn’t impressed by the 650. Same $199 get you the MassDrop AKG K7XX. GREAT headphones

  8. David

    I completely agree about prefering musicality over clinical accuracy. Next time I see this drop available I’m getting it.


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