The TH-X00 by Fostex & Massdrop
Build & Fit9
Value For Money9
9Our Score

Leave it to Massdrop to solicit a positive design alteration from Fostex that is both superior and cheaper than the original model it was based on.  Back when the X00 had first been announced, I’d thought it was going to be an entirely new product, or maybe a rehash of a previous model with shiny wooden cups.  Thankfully, we all received a little of both.  I rated the Lawton Fostex TH600 very highly in 2015 and never really expected to revisit basically the same headphone again so soon.  Alas, the life of a reviewer…

The Massdrop Fostex X00: The New Tuning

Side by side with the stock Fostex TH600, Massdrop’s new Fostex X00 is noticeably less recessed and more upfront in the midrange by a small degree.  However, it is still a recessive experience to say the very least.  Undoubtedly, it is improved and more enjoyable for sure and with extra midrange liveliness, but also still within the world of what most of us consider a V shape type of a sound signature.  They’ve also dropped the bass quantity and extension potential to a level that I find unsatisfying as bass enthusiast, but also one that vocalists and treble heads would appreciate more.   The amount of deepness and rumble factor has been cut out a bit and replaced with a more tolerant and mature low end.  Truthfully, the bass enthusiast inside me hasn’t stopped whining about it ever since the first time I’d heard this headphone and the TH600 is still the superior headphone on the low end, which seems to showcase audibly more quantity at nearly all times.

Why Massdrop was the required ingredient needed to force someone at Fostex to put extra love and care into a proper retune of a TH600 driver is just beyond my level of comprehension.  I can’t say that the X00 is absolutely and unequivocally a TH600 driver with some modifications, but I can say that the TH600 and the X00 sound nearly identical in quality across the board.  My gut instinct makes me feel that the X00 is just a TH600 with some tweaks here and there that alter the physical presentation of the headphone, but were simply all tweaks that left the yummy tonality, impact and overall feel of the TH600.


If that is the case, why the hell did Fostex not do this originally in the TH600?  Why allow the TH600 and the TH900 to become what the audio world considered the pinnacle of quality in a V shaped headphone for a few years and totally ignore everyone who said they hated the recessed nature of the headphone, but when Massdrop comes along…Fostex is happy to shell out an improved version?  This makes me want to go cry in the corner somewhere, as anyone who purchases the TH600 in recently times and doesn’t know about the X00 is getting a not so nice deal…me being one of them.  They had the ability to do this at the start, but chose not to.

Sound Quality

As mentioned, the X00’s bass quantity is dropped off a fair amount over the TH600, although it is still just within the realm of a bassheads delight in that regard.  You’ve still plenty of bass to work with and there is no audible difference in raw quality between the older TH600 and this X00.  At this point, I have to dispel the myth that the X00 and the TH900 share the same quality top to bottom…it just isn’t true.  The TH900 remains superior to the TH600 and the X00 by an audible degree in every facet of the word, or ear for that matter.

The TH900 offers noticeably more purity and cleanliness in the bass regions, as well as hefty, deeper reaching extension with gut wrenchingly bottomless bass tracks from TEB.  Sadly, the X00 can’t really reach that low and cuts off short of the mark by comparison to the TH600, let alone the TH900 that is even deeper reaching than the TH600! That rumble factor can drive so low on the TH900, that it makes me stand by my original statement I made years ago about it:  it is the deepest reaching dynamic driver, closed back headphone available.


The X00 headphone is still fast for a dynamic driver and can hit/slam with vivid appeal, so those interested in a relaxing and soft sound signature should not purchase this headphone or any of the TH series models from Fostex.  However, if you want a solid and engaging low end in terms of literal and physical impact level, consider selling a kidney and purchase the TH900.  Better to go big or go home, right?  If you want the more consumer oriented version of the TH900 and TH600, then of course drop $399 on the X00 and enjoy.  It does a fine job with bass and remains one of the best mid tier headphones ever designed and oriented for a bass enthusiast.  Just go into the purchase knowing full well that the TH600 and TH900 are superior in how deep of a dive the bass experience can actually reach.


Bass Quality

The low end sound quality of the X00 is sublime for the price.  What Fostex and Massdrop have done here is develop a better looking and tweaked TH600 for $399, but is now a few hundred dollars US cheaper than the stock TH600 with magnesium alloy earcups and problematic treble.  Clearly, something that most considered good to begin with that is now being sold for cheaper, yet with some improvements and alterations, is only going to drive the price to performance ratio into an even better positive light.  They’ve done just that with the X00.

In terms of bass quality, the X00 is still excellent and unaltered by comparison to the TH600, besting even the Nighthawk from AudioQuest and even my beloved Audio Technica ESW10JPN.  Although and to my bass enthusiast ears, too much quantity was lost.  Now, I require a +5dB boost on the low end at all times on the X00 and I think most bassheads would agree that the stock bass quantity just isn’t quite enough for us.  Still plentiful, but right on the boarder of what I consider basshead quantity levels…and being a sick son of a gun like me when it comes to bass…+5dB boosting on the bass is right where I feel cozy to bring the X00 back to the TH600 quantity level’s below the belt.


I hate V shape! So, let’s just get that out of the way before continuing.  I can deal with mediocre sound quality from other brands and in other headphones out yonder, maybe even some harshness up top…but I cannot handle recessed midrange.  Thank the audio gods that Massdrop coaxed Fostex into fixing the overly relaxed vocal experience in the TH600 with this new X00.  Yes, it was improved, but it is still too recessed for me.

Despite that, the headphone remains immensely solid feeling for a Dynamic headphone and that substance/physicality factor is off the charts good.  Not quite on the level of a lower end Planar, but still damned good for a Dynamic.  That heft quality is one of the few that my ears desire and require first and foremost, so I am happy to hear the X00 has not been altered enough to negatively affect the overall weighted appeal of the sound signature of the TH600.  Fostex does sound thickness and substance right, always has and hopefully always will in their future Dynamic headphones.

The headphone is still just a tad sibilant, but it is not at all a problem anymore.  Massdrop’s Fostex X00 is significantly toned down up in the treble region and by comparison to the TH600 and TH900.  Swapping pads from stock to the MrSpeakers pads results in a muted sound signature up top that loses all the nice improvements the X00 made over the TH600, so I don’t recommend you do that unless you want added comfort.

Nasalness was a problem in the upper midrange of other past models, but this is also no longer a thing here in the X00.  Testing the same track from Jamie Foxx called Vegas Confessions, you can instantly spot the differences between the X00 and the older TH600 with regard to vocals: the X00 simply sounds more polite and less sharpened, less prone to wince not only in the higher vocal tendencies, as well as the high hat strikes on the digital cymbals that appear mid-track.  The TH600 and TH900 are harsh on the treble, wince worthy and a bit too bright for my tastes and it seems like most of the community agrees with me on that notion.


Sound stage is relatively untouched in actuality, but there seems like a downgrade in airiness inside the X00 compared to the TH600.  It is very clear that this is due to the toned down treble of the X00 versus the overly plentiful and bright treble of the TH600.  With some proper EQ, you’ll never tell the imaging differences between the sets if someone placed them on your head without you looking at them prior.  There really isn’t much else to say here beyond the fact that the X00 retains all the wonderful traits of stereo imaging that the TH600 offered in the past.  It is very large sounding, plenty spacious in height and depth of field, but lacks a nice sense of width by comparison to all the other staging elements available in the X00.  It is not at all something anyone should ever gripe over, as the headphone is absolutely among the vastest sounding and aired out feeling closed back headphone out there.

The Woody Test

Somehow, Massdrop got Fostex to take a page from those custom woody cup shops and dropped in a lovely looking Mahogany woody of their own.  What bugs me about this is that the wood feels very low end, thin and very lightweight by comparison to my Lawton cups.  There is a blatant and obvious quality difference between them, but I can’t really use that as a legitimate gripe either to lower the end result score here.  If you aren’t planning to swap cups, you’ll never notice this even exists as a potential annoyance.  My Lawton cups are $600 per set and some of Lawton’s models are double the price of the entire X00 headphone.  Massdrop’s X00 clearly uses a lower end and faster production method for their wooden cups, which is easily detected upon handling both of them side by side.  They are still beautiful though, but the lacquer finish on the X00 cups can’t touch the Lawton’s.


Beyond exterior traits, I’d detected a solidity factor difference in the treble when comparing the Lawton cups installed on the X00 versus the stock cups of the X00.  Like a spot light shining in my face, it was beyond obvious that the Lawton’s dampening materials toned down treble significantly and in a more positive manner than what the stock X00’s wood cups without any dampening inside accomplished.  The sound of the Lawton cups on the X00 is superior to the stock Mahogany cups and they are also denser feeling and just right up top for me.  The Stock X00 woodies feel a bit splashier by comparison.

Final Thoughts

Truth be told, the X00 is just a retuned and newly adjusted woodified TH600 to my ears.  I cannot stress how upset I am at Fostex for not doing a great job with proper tuning on the TH600 and TH900 when they were first released.  Instead, Fostex blurted out a great looking headphone in both models, but both had an absurdly recessive midrange that broke the entire experience of the headphone.  I rarely used my TH600 after the review because of this and it just sat on my shelf and stand looking gorgeous with that woody from Lawton that I installed.  I just can’t handle V shaped sound signature as well as others.

Now though, I’ve a fantastic excuse to actually use nicer woodies with the X00. Looking back on it and revisiting both the Fostex TH600 and TH900 sets again, I don’t feel any different than I’d originally had when I reviewed them:  They are both the poster children of recessed driver sound signature for a closed back design.   My question is why on Earth did Fostex require Massdrop to come into partnership with them just to create what the TH600 should have sounded like all along?  Why didn’t Fostex listen to anyone previously who complained about it and why did this X00 have to exist through Massdrop…and not as a new Fostex product on its very own? They should have done this originally with the TH600!


Of course, I am very happy someone told Fostex they should improve on the design and tune things properly.  If not for Massdrop here, I’d likely never get to talk about the TH600 or TH900 again.  Despite the TH600 being highly rated, it had too much of a recessed midrange for me to fully enjoy and no amount of incredible pieces of Art from Lawton or Martin Customs would fix that for anyone. As for the X00, I can’t see anyone calling this anything but a fantastic deal!  I’ve found price to performance to exceed the original TH600 by a small factor due to the price drop and the addition of the nice wooden cups.  Massdrop did a nice thing here and I hope other companies follow suit in the near future.  For now, the X00 will likely retain the title of the best mid tier priced headphone deal available for the foreseeable future.  $399 for a better looking TH600 with wooden cups and slightly improved treble?  I’d pay that all day long and then some without thinking twice.

Price: $399.99


Technical Specifications

  • Fostex x Massdrop
  • Closed-back design
  • 50 mm dynamic transducer
  • Magnesium alloy construction
  • Mahogany earcups, brilliant gloss finish
  • Leatherette earpads, matte black
  • Magnetic flux density: >1 tesla
  • Impedance: 25 ohms
  • Sensitivity: 94 dB/mW
  • Maximum input: 1,800 mW
  • Frequency response: 5–45,000 Hz
  • 10 ft (3 m) thick, braided Y cable
  • 1/4 in (6.3 mm) gold-coated stereo phone plug
  • Weight, without cable: 12.3 oz (350 g)
  • Weight, with cable: 17 oz (482 g)

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  • breizh

    Hi Michael,
    is it better than the Oppo PM-3 ?
    And what about a comparison with the Beyer DT1770 ?

    Thanks a lot

    • 24bit


      I do not own the PM-3, but I’ve experience with it and often get to hear it. So, take this as a grain of salt type of a recommendation/comparison. I think the X00 and the PM-3 are very dissimilar headphones. The X00 is superior in stage size by a large amount, as well as bass quality. The PM-3 has a flatter sound, it is also less harsh on impact and more soft feeling overall. That is not to say it is a relaxing headphone, it still has bite, but the X00 just has noticeably higher levels of impact. I felt like the PM-3 and the NAD HP50 were equals for the most part, maybe either set taking a slight edge over the other in this or that way. But, the TH600 is the superior headphone overall to the lot. Bigger sound stage, more realism, more clarity top to bottom. The downside being the size of the X00 and the recessed mids. Those aren’t problems in the PM-3, which remains the headphone I’d likely pick for portable needs if I had to buy a “small, but still circumaural” headphone.

      I’ve also not heard that Beyer headphone yet, so I couldn’t help you on that front. My apologies, maybe someone I know in the future will tote one to a gathering so I can finally hear it. 🙂

      • breizh

        Thanks a lot, now I have to take the right decision… 😉

        • 24bit

          Fostex could learn a lot from Audio Technica and how they developed their older W series woodies. Recessed mids are just so lazy of a thing to allow. If Audio Technica is able to grant good bass quantity and forward mids, everyone else should be able to do so as well. Either way, the X00 is a good headphone, looks good, feels good, great value, mod friendly.

  • 24bit

    For reference, as this seems a debate on Head Fi after my article was posted there, +5dB is required on a bass booster like realbassexciter inside foobar2000 to get the bass quantity to match the TH600 stock bass quantity. I know +5dB seems like a huge number, but its not a 1:1 ratio of the dB level to what you can actually hear or feel. The X00 doesn’t respond that well to increasing bass quantity and a +5dB toggled up doesn’t actually mean you are going to get an audible +5dB in quantity.

    On a flat EQ, the Stock TH600 bass is the same as the X00’s bass quantity with a +5dB boost. With crossfeed active, this audibility actually lessens. Also thank you guys at Head Fi for the kind words on the review! Very appreciated 🙂

  • reachback

    Hey Michael,

    Do you recommend using iPhone as the source for this headphone, or maybe paired up with a portable amp? Because its impedance seems pretty low.


    • 24bit

      You’ll not need an amplifier to get sufficient volume from the newer iPhones out of the X00, so you’ll be fine with potential volume needs. However, with a little more voltage and generally a better sounding source, you’ll achieve noticeably more clarity, dynamics, staging properties and so on. It is a fairly efficient headphone, but the Fostex Bass in all the other TH series models really require more juice than what most portable sources can dish out. Volume and proper driving power aren’t the same sadly. The point of the Fostex headphones in the TH series is of course that yummy low end and to get it, you really do need more driving power in your source than what apple products are capable of. Direct out of the iPhone, you’ll get a shoulder shrug worthy experience all around and you’ll totally miss out on what the TH600,900 and X00 were meant to show off. But, even that shoulder shrug worthy quality is still going to be pretty good by comparison to the competition at this price point. The Fostex headphones are super snobs when it comes to how the bass can shift with proper driving power behind them, for example my iBasso dx90 is much more powerful than the iPhone and even it just isn’t something I feel okay with using direct with the X00.

      • reachback

        Thank you for answering! I’m thinking of getting the Thebit Opus#1. Have you tried this amp yet? If you have, could you briefly talk about it?

  • canali

    how do these compare to the sony mdr7520 and senn hd650?
    i love balance and detail, but with also some warmth and musicality

    • 24bit

      The Sony is a fair distance away from both in quality. The HD650 bests the X00 narrowly in raw quality, but it sounds significantly thicker in tone. The X00 sounds much thinner. The HD650 is also significantly softer with impact and physical slam in the bass and treble, meaning it is much easier to listen to without wincing. I’d still pick the HD650 over the X00 because I consider it the superior musical headphone. It is “warmer”, much more enjoyable and has more potential to alter it’s sound with different source and amplifier pairings. The X00 would is more stubborn in that regard.

      Out of the three, if you wanted musicality and a little warmth, then the HD650 is certainly the best bet.

      • canali

        thanks…but weren’t the sony’s 7520 were the company’s top monitor at the time…not to be confused with the lower end 7210 or 7206 i think.

        i’m just trying to find a good over all set of cans with great punchy bass, good low end, mods and airy treble (is that the stock phrase nowadays, lol)..great detail but still musical…for rock, jazz and blues…an engaging set of cans vs relaxed and ‘meh-ish’

        maybe i should also investigate planars?

      • canali

        thanks…so would you consider it a compliment to the 650 for those ‘basshead’ days?

        • 24bit

          The X00 sounds polar opposite in a few ways. The HD650 is thick feeling and slow on the draw, it is methodical and has softer impact and far slower decay. It is also not as bassy and is the more linear feeling of the two. The X00 is much thinner feeling with a more intense physical slam. It also still sounds a bit V shaped and has more bass quantity than the HD650. I very much prefer the HD650, but I think the X00 has superior bass quality and more quantity.

          Would it compliment it? Yes, I think so. Their bass experiences are tonally opposites.

          • canali

            thanks for your op and time..continued success with your site.

          • 24bit

            No problem. Always around to help 😉

          • canali

            must ask: have you compared it to the other ‘flavour of the day’ the new meze 99 classic closed back? that’s getting alot of buzz, too, for being quite the musical ride

          • 24bit

            Sadly no, I’ve not heard anything from that company yet.

  • piyanatk

    Hi Michael, I have read your review for the TH-X00 and Audio Technica W1000Z and obtained both headphones for my quest to find a perfect closed headphones for office use. I plan and should probably keep just one of them, but it has become a very hard decision as I like both of them in different ways. I agree with you that the W1000Z could have more sparkle in the treble, and I also hate the recessed mid on the TH-X00, but the recessed mid is not as bad as Beyer DT990, so it is acceptable for me. The cleanness and the bass in the TH-X00 is great, but the vocal in W1000Z is also great. If only I could combine both of headphones … I have had A900X, AKG 553 pro among others and currently owned Oppo PM-3. I am not quite sure what to do. I might just keep both of them for awhile until I can decide, or perhaps I should try W5000 …

    • 24bit

      The W5000 is not as good as the newer 1000z, at least not in my opinion. I’m with you 100% on your findings around those models, also in the same boat as to wanting a meshing and fusion of their best traits. Sadly, in the hifi closed world, nothing will suffice and nothing I’ve encountered has all of that. The best I’ve come to a musical and fun headphone with all those great traits is the Focal Elear, and it’s an open back.

      Compromise has to be made because I don’t think anyone invented a proper closed set that is over ear that achieves that desired sound. You can find it in iems though. Lots to choose from there, try the $75 TFZ S5…you’ll likely want to resell your ATH and the fostex after you hear it. Excellent staging, great mids, good treble and gut wrenching bass potential with clarity as good as some customs I’ve used. The only “closed” set that doesn’t really have anything too nasty or annoying is the Audeze Sine, but that’s an on ear model.

      This is a battle we can’t win, I’m afraid :[

      • piyanatk

        Thanks for a quick reply Michael.

        Can you be more specific about w5000 vs w1000z?

        Focal Elear is defenitely in my upgrade list for home uses.

        The IEMs suggestion is interesting. There are definitely more IEMs with all kind of sound characteristics to choose from. Comfort is what let me to use closed headphones. I pretty much have music on all the time, and putting IEMs in my ears for a long time is very uncomfortable. My left and right ear canels are also not the same size and shape, at least from how I feel. I tried all kinds of tips but they never insert equal pressure on both ears. I used to considered custom IEMs, but the added costs are too high for me at moment. Plus, you cannot really try custom IEMs.

        • 24bit

          The W5000 sounded hazy and unclean to my ear. I didn’t enjoy it in the slightest. The 1000z is more musical, more tame and more clean and clear from top to bottom. You’d be downgrading from the 1000z to the W5000.

          I have the same issue with my right ear as you, it doesn’t fit normally, which I why I went customs for the most part. But, I find the S5 and the comply tips a solid fit that don’t move at all. The included earguides help a lot as well with that. Cannot recommend this iem enough, it is worth looking into.

          Wish I could be of more help, but we are in the exact same boat. I cry daily for a closed back set that has good heft to the sound, a moderate to forward mids, very plentiful bass and solid treble that isn’t annoying. Such a sound doesn’t exist outside of the Audeze LCDXC. That is the dream headphone for us, actually. But even then…it’s so heavy and cumbersome.

          • piyanatk

            I will take your description of w5000 vs w1000z as something like hd800 vs hd600 then, or a border line of that.

            What do you think about Mr. Speaker Ether C/Flow C?

            The only IEMs that I have at the moment and are still using is Audio Technical CK100Pro. I tried it in Japan a few years ago and fell in love with it. It sounds very much like w1000z but a lot more revealing, even more than Beyer DT990 in my opinion, although colored and not as cleaned. The bass and treble are much more extended than w1000z. Being revealing, it sounds a bit cold, but all the Audio Technical euphoric touch is still there.

          • 24bit

            I’ve not heard the newer MrSpeakers products yet, so I couldn’t comment on them at all. Finding that tonality and midrange lusciousness outside of Audio Technica’s woodies is immensely difficult. To this day, the W3000ANV is one of my favorites for midrange experiences, it is very colored, very warm and mellow. The W5000 is dry as a bone and lifeless to me.

            Talking about this…you made me want to rebuy the ATH W3000ANV again. LOL*

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