Fostex TH-X00 Massdrop exclusive


Headphoneus Supremus
Pros: •wood, aesthetics
•fun sound signature
•deep extending bass with sub- and midbass emphasis
•good bass control with a strong impact and bass pressure
•soft ear pads
•nice soundstage - three-dimensional, open sounding
Cons: •non-detachable cable
•cable coated with woven material below AND above the y-split
•bad exterior noise isolation

Well, well, well – the Fostex TH-X00 Mahogany has been talked about countless times and was reviewed almost just as often. Why add another review to it? Welp, why not, that’s why. I won’t bother you with lame and boring company etc. info since a) you likely know them anyway, and b) if you’re really interested in this headphone, then you have likely done your own research.


I bought my TH-X00 Mahogany new (I never buy used headphone-related gear because I find that disgusting) in 201x (don’t remember – might have been 2015) on Massdrop with my own money and paid just a tad less than €500 including import fees (in total, it was €498.xx if my memory serves me right). I reviewed the woody some time later – in a different language. Now I have translated large chunks of that very review into English and yeah, here it is.
If some sentences appear weird to you, then it’s likely either because I’m not a native English speaker, or because parts of the review and some sentences were machine-translated (even though I re-read every translated sentence and corrected a lot).

Looks, Feels, Build Quality:

Great looks and build. Light weight thanks to magnesium. Nice wood grain and varnish. Slight visual minus: wooden “gap” between magnesium frame and cups not varnished.

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Permanently attached cables – would have wished for replaceable ones at the price point and no cloth/suede/nylon/whatever-it-is coating above the y-split, but whatever.

Comfort, Isolation:

I have large ears. Nonetheless I am surprised to say that I can the soft ear pads to seal well and achieve a comfortable fit.

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Clamping force is rather moderate, nonetheless the headphone doesn’t really move unintentionally.

Those who intend to use the Fostex outside should reject this idea directly, because even if the TH-X00 is a closed headphone at first and second glance, it has a surrounding ventilation slot on the magnesium ring. Correspondingly, it only isolates very moderately - a laptop's fan noise is slightly attenuated, but even a relaxed use in the garden on a sunny summer's day is impossible if you want to isolate yourself from the environment.



The Fostex is clearly a fun headphone with a present, impactful low-frequency accentuation, especially in the mid- and sub-bass, combined with an accentuated upper treble. If you are looking for a linear or mostly modest tonal tuning, the TH-X00 is clearly the wrong choice.
Nevertheless, it does not exaggerate excessively with the tuning otherwise, even if it is still a good deal away from a natural tuning (natural in the sense of "not too far away from neutral sound" in this context).

At about 500 Hz, the accentuation of the low-frequency, which from then on rises steadily downwards to 60 Hz, where the climax is located, starts. It is remarkable that the level underneath can still be kept constant and the TH-X00 Mahogany doesn't roll down below 40 Hz, but can keep the level almost constant down to 20 Hz. That's pretty great.
Due to the fact that the accentuation of the bass range increases steadily and gradually, the sub- and midbass have more level than the upper bass and fundamental, which is why voices are not unnecessarily thickened or overshadowed. The upper and upper midbass still have a bit more volume to speak of a "pure"/exclusive sub-bass boost, although the Fostex is probably one of the few headphones, if not the only one, that comes closest to it (a pure sub-bass only elevation).
At least this gradually increasing accentuation works very well with a steadily increasing bass pressure (even if for my personal taste the upper bass and lower fundamental range could sometimes be calmly dialled back by about 3 dB, to bring out the sub- and midbass even more).

Anyway – compared to a really neutral and flat tuned listening tool, the Fostex has an accentuation in the sub- and midbass, which is about 8 dB in quantity, if you achieve a good seal, which at first glance may not even seem all that much, but actually expresses itself more strongly, because the Fostex can build up quite a lot of bass pressure (possibly also by the large drivers and the closed cabinet, but mainly since its bass elevation isn’t exclusive to the sub-bass but also features a powerful, strong midbass).

At 1 kHz there is a rather flat bump, only really noticeable with sinus sweeps, which I already know from my Fostex T50RP Mk3, followed by a small dip at 4 kHz, a small hump at 5 kHz, another small dip between 7 and 8 kHz and finally a stronger broadband emphasis between about 10 and 14 kHz.

Not all that much surprisingly due to its fun smiley-face v-shape tonality, voices appear to be rather somewhat in the background in the mix without showing any real unnatural timbre or coloration from the treble or low frequencies since the elevations are set very high respectively quite low.

Despite the emphasis, the treble is generally perceived as rather inoffensive, which is due to the fact that the boost is located very high with the placement in the starting super treble, thus bypassing typical sharpness-causing frequencies between 7 and 9 kHz.
Nevertheless, the TH-X00 Mahogany doesn't necessarily have the perfectly natural upper treble and some percussion elements sound a little thinned out, but without getting sharp at all.

- - -


Yes, the TH-X00 is clearly a “fun” tuned earphone that is especially enjoyable for listen to electronic music, hip hop/rap, better-mastered rock and pop and drum & bass, while more intimate or voice-heavy recordings with a high focus on the linguistic content (or "typical audiophile test tootling"...) seem less suitable, while there are of course no limits to personal tuning preferences.

If you are looking for a headphone with a strong, deep reaching bass in combination with a bright, but not sharp or unpleasant starting super treble and a midrange with an overall pretty correct timbre with voices appearing overall more in the background in the mix, chances are high that you will enjoy the Fostex x Massdrop TH-X00 Mahogany (very) much! I pretty much knew what I was getting before I bought my TH-X00 Mahogany, and I wasn’t disappointed at all.


The Fostex does justice to the price in terms of resolution and delivers the performance that one would expect to find for the price.

While it doesn't quite make it into the class of a Sennheiser HD 800 (the Fostex lacks a little bit of separation in the highs and the last bit of tightness in the bass compared to Sennheiser's open-bacl dynamic driver headphone flagship), it surpasses popular ‘phones such as the Beyerdynamic DT770 Pro (250 Ohm) or Meze 99 Classics in terms of overall resolution.

All in all, I see the TH-X00 Mahogany more or less slightly above the level of my HiFiMan HE-400 in terms of resolution, whereas that one is still somewhat tighter and faster in the bass than the Fostex, nonetheless the TH-X00 delivers more sub-bass presence for sub-bass enthusiasts due to the gradually increasing accentuation in its lows (although sub-bass enthusiasts should also enjoy the HE-400 because just like my Audeze LCD-X, it manages to extend its bass linearly into the sub-bass without rolling off) and it isn’t soft in the bass at all but rather tight for a dynamic driver model, and especially very well controlled.

The bass of the TH-X00 remains well controlled and nimble despite the powerful boost, even with faster and more demanding recordings. The headphone with dynamic drivers even belongs to the faster and tighter models and only appears a little soft in comparison to the tight dynamic bass of the Sennheiser HD 800 or tight bass of the orthodynamic HiFiMan HE-400.

The midrange resolves well and only appears a little “dry”/matte due to the v-shaped tuning - on the other hand, there is absolutely no lack of details in the mids, and speech intelligibility or the resolution of smaller linguistic and vocal details don’t leave anything to desire.

The treble of the headphone that emerged from a collaboration between Fostex and Massdrop, does not lag behind the midrange and bass in terms of details either and does not seem strident or sibilant due to the skilfully done placement of the accentuations as well as due to the good level of details. One could perhaps only criticize the fact that high treble notes appear to fade away a little too quickly and that separation up top, if you are used to in-ears with Balanced Armature drivers, does not have the same precision.

The Fostex still “wants” to be fed with rather well recorded and produced music material, since it doesn’t “harmonise” all that well with badly or flat mastered and overdriven recordings, because it doesn't exactly cover them up very well (in the presence range and middle highs, there is no smooth and “romantic” recession, making the Fostex point out flaws rather directly unlike for example the LCD-X where bad-ish recordings are still listenable thanks to where its recessions and dips placed in the presence range/upper midrange and treble).


For a closed headphone the TH-X00 Mahogany has, at least for my ears, a very well-done and open soundstage presentation.

In comparison with some popular open headphones up to about 400€ (for example Sennheiser HD 600, AKG K701, Beyerdynamic DT880 Edition (600 Ohm)) the spatial reproduction of the Fostex does not appear quite as open, but rather average, but on its own it has a (very) good spatial reproduction for a closed-back-ish headphones, which is bigger and more open than with many closed headphones. Therefore, it also breaks the imaginary border within my head and extends outside.

The stage of the TH-X00 Mahogany has a very well-balanced ratio between depth and width and is by no means flat. Partly the tonal tuning contributes to this, but even with "neutralised" with the help of some EQing, the convincing impression remains and the Fostex keeps most of its spatial depth.
It's nice to note that there are no audible signs of undesired reverberation reflections at all, as some closed headphones can appear to have to a lesser or greater extent.

The stage of the Fostex also convinces me in regards to instrument separation, control of densely populated, fast and complex recordings, accuracy of layering as well as the reproduction of emptiness between individual instruments. Yeah, its soundstage is one of the Fostex’s strengths.


The Fostex x Massdrop TH-X00 (Mahogany) is a very good looking and feeling headphone that is tuned for fun and brings a powerful, deep set and well controlled (especially sub-) bass which is balanced by a high, bright but not sibilant accentuation of the beginning super treble range.

Coupled with the open and precise three-dimensional reproduction, especially noteworthy for a closed-back-ish headphone, this model, which is exclusively available from Massdrop, is a great recommendation for a fun headphone for those moments when neutrality and a modest, flat tuning are not desired.

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By the way, fans of the Beyerdynamic DT770 Pro are also likely to like the Fostex very much, because in my opinion it represents a direct upgrade to that very German headphone (while having a stronger emphasis on the true sub-bass, a less unnatural/metallic high frequency range, audibly higher resolution and a more precise, more open stage).

The only things left to be desired would be replaceable cables and better isolation of exterior noise – but it seems that Fostex has taken care of the first issue with the introduction of the TH-610.


100+ Head-Fier
Pros: Good deep bass quantity, good build quality, great looks, comfortable.
Cons: Long non-detachable cord, sound leakage, bass can become muddy, treble can become shrill or sibilant, midrange recessed.
Massdrop Fostex TH-x00 Mahogany

I will start this review by stating I have always been on the search for a sub-$1000 pair of headphones (used or new) that have all of the things  I believe the holy grail of headphones should have: crisp detailed highs, well defined and accurate mids, and enough bass to give a solid foundation with an accurate and detailed soundstage (for headphones). In search of this I've owned a lot of high-end headphones, and speakers, over the years including:

  1. Audez'e LCD-2
  2. Audio Technica ATH-AD2000
  3. Audio Technica ATH-M50
  4. Beyerdynamic Tesla T1
  5. Denon AH-D2000
  6. Denon AH-D7000
  7. Fostex TH-600
  8. Grado HF-2
  9. HiFiMan HE-500
  10. Sennheiser HD650
  11. Sennheiser HD800
That being said, I've never been able to find that elusive all-in-one holy grail headphone. While the planar magnetics came close in the sound department the weight and overall comfort was lacking for long listening sessions. One could also argue that the HiFiMan cable system was also very troublesome. Connectors were problematic, wires would get twisted easily, and so on. My Tesla T1, HD800, and AD2000 fared much better in comfort easily being the most comfortable headphones I've ever owned and all of these also had superb soundstaging thanks to their open back designs. However, The overall lack of range, especially low end, and sibility of the treble on these 3 headphones proved to be areas for improvement in my mind. When I heard that Massdrop and Fostex were coming together to provide the TH-x00 headphones I was intrigued, but wondered what $400 (retail mind you) headphones could get me. As this review is evidence of is the fact that I decided to put the Fostex TH-x00 through my intense level of scrutiny. So anyways, without further ado, on to the review:

Specifications, from Massdrop:
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)


Physical Build Quality

The Massdrop Fostex TH-x00 headphones are an impressive looking set of headphones. The build quality of the Massdrop Fostex TH-x00 is fantastic for the price, very good and solid. Most of the structure of the headphones is magnesium alloy. The headphones are easily adjustable and have notches in the metal supports at each location so that the headphones can lock in place at each location. The one ding I will give on the frame, the same problem which has plagued similar Fostex and Denon headphones, is the single pivot pin between the yoke and the headband. The pivot pin feels inherently weak as it has in previous designs. That's not to say that it is weak, but just that it feels like the headphones could break at the junction much more easily than in other locations. The headband has a minimal amount of padding and is covered in what appears to be synthetic leather or pleather. The earpads are made from the same material as the headband, the padding in the earpads is adequate. The earpads have a slight front to back wedge to them, placing the drivers at a slightly forward facing angle when on your head. I will state that the inner cut out shape of each earpad is not circular but more "O" shaped in nature and offset towards the front of each side. While this was not an issue for me, someone who has relatively small ears, this may be a problem for someone with larger ears. The cord....oh the cord...well first it's not detachable and second it's way too long. At 10 feet, I can't see anyone ever being able to use these as anything other than for home or studio use, and even then the cord still seems too long. I could literally get up from my desk and walk from one wall of the room to the other and have no issues with the cord being too short, it's that long. I will also say that while the main thicker cable doesn't suffer from microphonics, after the break into the two smaller cords up to the drivers, these wires have worse microphonics than I would like from a set of headphones costing $400. Rubbing against your shirt or touching it during normal use will lead to an annoying rustling sound. That all being said the pieces de resistance of these headphones are definitely the beautiful high-gloss mahogany earcups. These things are absolutely gorgeous and, to me, look much better than what was depicted on the Massdrop page. While no two will be alike, given that the mahogany is a natural and unique material, I can't imagine these looking bad. 

Overall, I would give these headphones an 8/10 for build quality.

Things to improve would be the pleather covering on the headband, and earpads. and the rotational pin at the yoke that seems weak. The cord length also needs to be adjusted and detachability is also lacking.


These headphones are very comfortable for their size. They definitely are not lightweight, but I wouldn't call them heavyweights either. They are somewhere in between. In comparison to headphones like the Audez'e LCD-2 or HiFiMan HE-500, with their much heavier drivers, these headphones are much lighter. At first, I was concerned with the small amount of padding on the headband when I originally received these, but overall the headband is comfortable and the weight does not seem too much for the thin padding. How this wears over time will be interesting to see as the upper part of the headband feels like a solid band of either metal or plastic that could potentially wear through the pleather coating over time. The clamping pressure on these headphones is reasonable, if not fairly light given the weight. The stock earpads are relatively comfortable, but I could see them becoming sweaty in hotter summer weather as I have a feeling that the synthetic leather probably will not breath that well, but that is an assumption at this point. Ultimately, while I wouldn't put them on par with what I consider some of the most comfortable pair of headphones I've ever worn, the Beyerdynamic Tesla T1 or the Audio Technica ATH-AD2000, I would put them several notches above something such as the Audio Technica ATH-M50 which have much stiffer stock earpads and put more clamping force on the sides of your head. As stated above, I would also put them leaps and bounds ahead of Audez'e or HiFiMan planar magnetic headphones, which weigh substantially more and will put more weight on the top of your head through the headband, which can be too much for some people.
I give these headphones an 8/10 for comfort.

Sound Quality

So let me get this out of the way first: The straight out of the box sound quality on these without any Amp/DAC is not good for their price. If you plan to use these without an Amp/DAC on computer, on a portable listening device, or other piece of audio equipment that does allow for additional power to be supplied to these headphones, you will disappointed. When trying this on several devices including straight from my computer, on my portable audio device, and from my phone left me asking what was to like about these headphones? The treble, compared to even my ATH-M50, was severely lacking in many instances, which left me feeling like I was missing parts of the recording. Mids and bass seemed muddy albeit very forward. But why should we expect a $400 pair of headphones geared towards audiophiles to perform well in these conditions? Frankly, we shouldn't. If you're going to spend this kind of money on headphones, they certainly deserve to be driven by an appropriate source with good audio quality. Given how ridiculously long the cord is, and the highly polished ear cups, I wouldn't see why someone would want to travel with these anyways. Therefore, the rest of this review, in regards to sound, will be on my current home rig.
Testing rig:

  1. Schiit Jotunheim w/ built-in DAC connected to computer through USB set to High Gain, volume at approximately 12 o clock.
  2. Music files are all lossless, FLAC, or at the very least 320kbps files 
  3. Sound comparisons will be made to some of my current headphones


Overall, when plugged into the Jotunheim, treble becomes more present. On songs such as Peter Gabriel - Apres Moi, which has strings, brass, and the lovely vocals of Peter Gabriel. The high end becomes more pronounced and defined. Mids slightly more recessed and bass less muddy than without proper sourcing and amp. Overall, I would say these have a "U" or "V" shaped sound profile, but would argue that the bass is more present than the treble. Even with a proper amp, I feel like some sibilant highs in sounds, such as from Melancholia from the Sicario soundtrack, are lost. That all being said, let's break this into categories so that my own review doesn't get too muddy itself.

Bass Quality/Quantity

First and foremost, you may be asking yourself: "these are Fostex, how is the bass?" To answer that I will say that, for the price these are at, the bass quantity is very good. That being said, if you are a basshead I still think these headphones will keep you longing for more. These reach very deep into the bass spectrum, but cuts short of similar headphones such as the Fostex TH-600 or TH-900. 
In regards to quality, in my opinion the bass can become muddy and less defined or punchy than I would like on certain tracks. Furthering that, even on tracks where the bass is deliberately more punchy such as on EDM tracks, I would continue by saying the bass is less well defined than my ears would prefer. Tracks like Miike Snow - Genghis Khan make this very noticeable. While the snare and bass drum kicks seem relatively well defined, the background bass seems to reverberate much longer and wider than I have heard on other headphones. Headphones that have arguably less bass quantity such as the Audio Technica ATH-M50 performed much better on these types of tracks when it comes to accuracy, albeit with less quantity and low end. On tracks such as Kings of Leon - Waste A Moment, where there is a lot of high end guitar action, drums, and heavy bass guitar further this point leading to an extremely muddy performance that lacks definition and precision and often seems to get interfered with when a lot of action is happening in the mids and highs.
Overall, I would give these:
5/10 for bass quality, mainly due to the inherent muddiness or bloated nature on many tracks.
8/10 for bass quantity, not as good as some closed backs, but good given the price range
6.5/10 for bass overall, grading quality and quantity evenly


As eluded to earlier, the mids are definitely recessed due to the "U" or "V" like sound signature of these cans. That being said the mids are still pronounced enough to be likeable in a lot of situations. Normal male vocals such as Rob Thomas from Matchbox Twenty on If You're Gone sound good and are relatively forward. However, when you start venture upwards to someone like Billy Corgan from Smashing Pumpkins on Disarm, or to even higher heights such as Bon Iver or female vocalists, the mids begin to lose body and substance and the recessed nature becomes much more prevalent.

In regards to the treble, I believe the bass is definitely more pronounced than the treble leading to my statement about the V shape not having the same legs on both sides. I've had mixed reviews in regards to treble with these cans depending on the track. In some instances even with proper source and amping, I have felt parts of songs sound different mainly due to the treble being more recessed than what I am used to. However, in some instances, the treble has seemed extremely sibilant and shrill, almost to levels that are unpleasant. Albeit, not as bad as the TH-600 before it. An example of this is in Puscifer - The Remedy, at around 1 minute there is an accompanying keyboard in the background that on my Audio Technica, Beyerdynamic T1, and even planar magnetics is extremely well defined and forward to a point of almost sibilance. These headphones leave me searching for that same sound, it's there but definitely much more recessed than on other cans.

Overall I would give the Mids a 5/10 as they just are not as forward across the spectrum as I would like. In tracks where both female and male vocals were present such as on the aforementioned Puscifer - The Remedy the vocals smear and the female vocals become more recessed than Maynard's male vocals. To me this leads to a lack of mid range detail which I do not prefer.

In regards to the treble, it depends on what your tolerance level is in terms of sibilant highs. While I think overall the highs are presented nicely, I also believe that it is track dependent, and when they really shine through they can become too sibilant and therefore too much for my ears.

I would give the Treble a rating of 6/10 based on the idea that you like to hearing the highs in songs and are willing to put up with sibilance in some tracks. Should you be sensitive to treble, this would receive a much lower rating.


The sound stage on these cans is not great. Given that they are "closed back" headphones, albeit these particular headphones leak a lot of sound, I don't think we should expect an immense sound stage. In regards to closed back variants, I would put Mr. Speakers Alpha Dog/Alpha Prime as some of the best in this category, but those headphones also have a very unique internal structure inside of them to do so. The level of airiness is lacking, and the sound stage overall feels very forward. I would say that the sound stage is center of your head in regards to how confined it feels. Separation of instruments on orchestral tracks, or tracks where a lot of vocals and different instruments are present is lacking. In certain instances it almost feels like all of the instruments are stacked on each other playing towards you from the same location and distance leading to an overall lack of width in the sound and also a lack of precise placement.

Sound stage gets 5/10 considering comparable closed-back headphones listed above.

Final Thoughts

I've read many reviewers say that these are "end-game" headphones. These are by no means "end-game" headphones.  The mid range will be too recessed and lacking detail for most. Furthermore, depending on the track the bass and treble seem to have varied issues (bass in muddiness and definement, treble in lack of clarity or too much shrill sibilance.) Furthermore, details such as the ridiculously long thick cord and amount of sound leakage these have, make these headphones virtually unusable for anything other than home use. While that is not a deal breaker for me in particular, I can guess than many head-fi'ers would find this one. While overall I am not disappointed at all for $400, given the gorgeous craftmanship, and overall comfort of these headphones, when it comes down to the nitty gritty of sound performance, these headphones have many areas for improvement. Even in my list above, I have found better headphones overall when compared to the Fostex TH-x00. Given that you can find LCD-2, Tesla T1, ZMF's, or Alpha Dogs used for only slightly more than what these sell for, and can obtain used HiFiMan HE-500 or new HE-400i's at a comparable price point, I would recommend looking elsewhere.

  • Like
Reactions: Jazz1 and volly
Thanks for being honest in your review, nothing beat that.
How long have you had these prior to writing your review? Did you put hours into the headphone? Also something about these being used with the Jot in high gain seems off..
great review. My only question: is there such thing as an end game ANYTHING in this hobby? :)

Hunki Chunki

100+ Head-Fier
Pros: GOOD bass. Great cable. well made.
Cons: Treble gets a bit hot sometimes. Earpads were too small for my jumbo ears
Another wonderful Massdrop exclusive. This headphones sound great amped (Schitt Stack and Grace Design M9xx)
The bass in this headphones is just.... a beautiful thing, not over the top but man... so... thick.
Treble and mids are good, thought the highs got a little hot at times.
The earpads were a bit too small for me, so a change to the ZMF omni sheepskin fixed that right up.
Comfort is great, the NON-removable cable is also really high quality.


500+ Head-Fier
Pros: Great mid-range and bass for rock and metal, comfort, value, looks
Cons: A missed opportunity to surpass the Denon AH-D7000
It’s Black Friday, and what’s more black than to buy a good pair of headphones for your favorite rocker or metalhead. Today the headphone audiophile community is buzzing about what may become a historic event in headphone history. Massdrop and Fostex have collaborated to create the best value in closed back headphones you can find today, with the Fostex TH-X00.


This isn’t the first time Massdrop has collaborated with an audiophile headphone manufacturer. Will Bright, who participated in the Head-Fi forums since he was a teenager, is the head of Community Expansion at the San Francisco company, and initiated a collaboration with AKG to create a special version of their 65th anniversary limited edition of their K702, which was a big hit in 2012. The resulting AKG K7XX Massdrop Limited Edition Headphone was assigned an MSRP value of $650, but sold for only $200 with Massdrop, a pretty amazing deal. In this case, it sold in only a run of 150, but more drops have been scheduled due to popular demand. A similar collaboration happened recently with the Grace Design x Massdrop m9XX DAC/Amp, a simplified $500 version of an amp that normally sells for $2,000.

I was tempted by these offers, but I already have the AKG K701 which I’ve used mainly for TV and movies in the living room for the past 9 years, and do not need another amp. However, the Fostex TH-X00 has inspired me to do my first drop. For years my favorite workhorse had been the Denon AH-D2000, great bass response for doom, midrange for rock and metal, and just enough detail but not fatiguing. The Dx000 line was designed by another well regarded Japanese company, Fostex. In 2009 they were the best closed back (semi-open) headphones around, an important evolution in headphone design that opened up a whole new segment of the market. The headphones were so popular that they fueled a whole additional side industry of modifications, for hobbyists who liked to switch out the earpads and cups for their own customized versions provided by companies like Lawton Audio.


The partnership with Denon ended quickly, by 2012, when Foster (the parent company of Fostex) decided to pull the licenses for their designs from Denon and focus on marketing their own Fostex TH-600 (originally selling for $1,000) and TH-900 ($1,200). Fans of the much more reasonably priced Denon DX000 line (starting at $350) justifiably felt abandoned. Today they are finally offering an olive branch to those customers by teaming up with Massdrop and creating a new design, the TH-X00, that is both a nod toward the popular “woodies,” the Denon D5000 ($699) and D7000 ($999) with their mahogany cups, and not only using elements from the Fostex TH-600 and TH-900, but even improvements, all for the amazing price (via Massdrop only) of $399. It claims the MSRP is $1,000. If that’s true, then that’s an incredible 60% discount that they’re selling it at, with a headphone that in most regards surpasses the TH-600, and in some respects the TH-900 and old Denon Dx000 line.

The past few years I’d been looking for a used pair of D7000 for a good price. I’d known people to find it for $400. Unfortunately it now mostly sells for $750 used, and that’s just too much for me. So the introduction of the Fostex TH-X00 is really exciting. It’s not the exact same tuning as the Dx000. Reviews have stated that the bass emphasis (thought not necessarily the extension) is mitigated in order to improve the midrange. Some bassheads should still be satisfied as it’s still very deep, while others may still believe it’s worth it to pay the extra money for TH-600 (which now sells for $600), TH-900 or a used Denon. However it should be good news for most metal and hard rock fans, as the midrange is very important for guitar music. And no less important is the bang for the buck.

I signed up for this drop as soon as I got up this morning and it was already at 1002. It’s now at 1322 as I finish writing this. 1950 units are available in this drop, so it will be sold out probably within the day. But they will certainly do another one as soon as their production catches up. Here’s a review:

While it is an astounding deal, they aren’t necessarily an endgame (a perfect headphone that suits all your needs for your lifetime) headphone for everyone. There’s plenty of great options, many more than when I last wrote about my latest Cans of Doom two and a half years ago, the Beyerdynamic DT 770 Pro. Since then, I tried out the Denon AH-D600 and did not like their tuning, and the fact that they looked to much like Beatz. I then sprang for a used pair of the famous Audeze LCD-2 v.2. In many ways, they were the most interesting headphone I’d ever experienced. They use updated planar magnetic and orthodynamic technology that was popular in the 70s, but faded when manufacturers found cheaper ways to make headphones. By the 2000s, Fostex was the only manufacturer that used orthodynamic technology, until Hifiman entered the picture in 2007 with the HE-5, and Audeze in 2009 with the LCD-1. My LCD-2 v.2 was released in 2013, definitely has a unique sound signature, with deep, luxurious bass response, rich midrange, and a rolled off high end that decidedly excludes them for use as professional reference. These are open headphones meant to be enjoyed at home for those who’s idea of fun is to re-listen to their collection through the unique filter of the LCD-2 tuning. And yeah, they go great with most metal, particularly doom.

They were a hit, and Audeze has since come out with several more models, with rapidly increasing price tags. While the latest edition of LCD-2 with fazor technology has gone down a bit to $995, there’s also the LCD-X($1,699), LCD-XC ($1,799), LCD-3 ($1,945) and LCD-4 ($3,995). I spend a huge portion of my life listening to music, and I do think it’s worth spending some money on, but even I can’t yet justify that much. Not when you can get headphones that perform nearly as well for far less. Additionally, the main drawback, at least for my LCD-2, is the weight. They are so heavy, that after an hour or so, the top of my head starts to throb and ache. I could mess around with alterations, but I decided it was time to sell them via the Head-Fi community and try something else.

A couple weeks ago, I became interested in the ENIGMAcoustics Dharma D1000. It uses an intriguing hybrid of electrostatic and dynamic technology. The result is supposedly stunning bass extension (5 Hz) and high frequency range (40 kHz). What really caught my attention was when renowned audio engineer Bob Katz, in a blind listening test, rated it third in a group of headphones all priced significantly higher than it’s proposed $1,200 price (he had a prototype). It was ranked between the Audeze LCD-3 and Sennheiser HD 800, and also beat out the likes of Hifiman HE-1000, Stax SR-009, Audeze LCD-X and Mr. Speakers Ether. However, no one in the Chicago area has the headphone that I can audition, and I just can’t justify paying that much for a headphone right now. Perhaps in a couple years I can snag a used one for half the price. Still, it’s innovative technology that can compete with headphones priced as much as $4,450 is exciting. It’s a good sign that competition will make prices more competitive.

In the past couple years, an enthusiastic Head-Fi member from Moscow who goes by levap took on the ambitious task of auditioning dozens of headphones and rating them for their compatibility with various metal genres. As expected, my favorites, the Denon AH-D2000, Beyerdynamic DT 770 Pro and Audeze LCD-2 fared very well. While his overall favorites seem to be the D7000 and the Abyss AB-1266, which goes for a whopping $5,495, I took special note of the Philips Fidelio X1, because if their value, and the fact that many others in the headphone community have compared the newer X2, released in 2014 for $300, favorably with the likes of the LCD-2. They do have a somewhat similar tuning, an open headphone that reaches sub-bass depths possibly even deeper than the LCD-2. And like the LCD-2, they are known for their dark sound, meaning they do sacrifice some detail in the treble, compared to even the Denon AH-D2000. But for those looking for that sound, they are an amazing deal. And what sold them for me is they are much lighter and more comfortable than the LCD-2, with a self-adjusting headband along the lines of the AKG K7xx series, and memory foam earpads. During extended wear, I can nearly forget that I’m wearing headphones. Of course that can backfire if you’re not careful, as it’s important not to play at loud volume for extended periods. I usually don’t listen at high volume for more than 20-30 minutes, then I gradually turn down the volume. If I’m doing a marathon listening session of more than 3-4 hours, I take breaks and switch to speakers (which at night have to be at pretty tame volume).  Who knew that the same manufacturer as my electric toothbrush would knock it out of the park with headphones? For the $300 price point, the Philips Fidelio X2 is probably the best option for metal and hard rock, unless you’re a fan of the Grado sound. I am not, as I find them harsh and fatiguing, and uncomfortable. Also, they still look like they were made in someone’s garage, which holds a certain rock ‘n’ roll charm for some, but not me.

Also worth mentioning is the Beyerdynamic DT 1770 Pro, which just came out in September. Judging from it’s model number, I presume it’s meant to be an update of my favorite Cans of Doom, the DT 770 Pro. However, these are different in that they use the Tesla 2.0 drivers famously used in their famous T1 Tesla headphones (originally listed for $1,399, but on sale at the moment for $699). Also much different is the price, at $699, more than twice the cost of the $299 DT 770 (which can be found easily for under $200). However, every component is easily replaceable, including removable cables, which make them a great, durable option for professional reference quality headphones with great bass extension. I have not yet heard them myself, but reviews so far have been very positive.

Another category worth exploring is portable headphones. The latest and greatest generally are smaller, sealed so as to keep out most exterior noise and avoid bothering those around you, and with removable cords with controls and a microphone that work with your phone. After selling off my venerable Audio-Technica ATH-M50 and doing some research last year, I tried and rejected the Denon AH-D340 (lack of bass extension), and settled on the NAD VISO HP 50, which lists for $299, and is currently available for $249. I also considered the V-MODA Crossfade M-100 and Sennheiser Momentum. I’ve been very happy with NAD, who are of course veterans in the audio world in regards to amplifiers and receivers (I use their C 355BEE integrated amplifier in my doomcave listening lair), but fairly new to headphones. They are nearly as comfortable and light as my Denon AH-D1001, but sturdier for outdoor use, and better noise-isolating properties. What seemed to give them an edge over others according to reviews, was their RoomFeelTM technology, which creates a much wider soundstage than other headphones in that category. I have to agree that with some music, you can imagine being in the room and hearing instruments come from different directions. This would probably make them suitable for movies too, if I were to invest in a smart pad/tablet. This past year my use has been limited to FLAC files on my little Zip Clip+, and streaming Spotify on the iPhone. Bass extension is excellent, though not quite as deep as my Denons.

For many, $300 is still an insane amount to spend on headphones. Fear not, there are still great affordable options. Often neglected in the hype over the legendary Fostex-designed line was the Denon AH-D1001. Listed at $149, I got them for around $80 new from Amazon, and they are what inspired me to also get the D2000. For relatively small on-ear headphones, their bass extension is incredible, I’d say at least 95% as good as the D2000. They are also the most comfortable headphones I own, which is why I keep them at my bedside, as I can lie back on my pillow with them on and listen and read with total comfort. Fortunately, when Denon lost their licensing with Fostex, Creative was able to carry on the design with just a couple small changes and improvements. The Creative Aurvana Live! lists for just $99, and can be found currently for $57.50, without a doubt the best value in headphones at that pricepoint. Another popular option is the Fostex T50RP Semi-Open Dynamic Studio Headphones for Commercial Recording and Critical Listening Applications, which list for as low as $99. A whole industry has also arisen based on making modifications to these headphones. The latest version, the Fostex T50RP MK3, was just released last month, and lists for $200, and can be found for $160. Many claim this is the best sounding headphone available for under $500, and I would love to audition them and compare to the DT-770 Pro, Fidelio X2 and of course the TH-X00.

There are literally hundreds of other viable options, as I’ve been focusing on headphones that work best with metal and hard rock. Sennheiser, AKG, Sony, Audio-Technica, Hfiman and many others also make great headphones.

I should note that with the exception of the Audeze and Beyerdynamic DT 770 Pro (250 Ohms), most of the ones I’ve personally used can perform fine from your phone or computer. A dedicated DAC (digital audio converter) can improve on the sound, and the increased power from an amplifier can resulting in scaled, better performance from many of the headphones. However beware of this rabbit hole! There’s a fine line between what is cost effective, and what is completely ludicrous and frivolous. I admit that I drank the kool-aid and, in order to drive my Audeze, invested in a Meir Audio Corda Classic amp and Daccord DAC setup. While not nearly as expensive as other compatible rigs, it also wasn’t cheap, it took 20 days to arrive due to customs. On the other hand, it looks and sounds great, especially with the Audeze. If I were to simplify, I would probably opt for the Grace Design m9XX via Massdrop, which, like the Meier, still offers crossfeed, which I believe helps alleviate headphone fatigue (basically it simulates how you would normally hear speakers in a room with natural crossfeed, the theory being that hearing completely separate left and right channels makes your brain work harder to make sense of it). However my Meier setup works nicely as a pre-amp to my stereo amp and loudspeakers too.

Some audiophile hobbyists have no problems with tinkering with amps, upgrading and collecting. I, on the other hand, simply need uninterrupted time with my tunes. So before you go in too deep, consider a starter like the Creative Soundblaster X-Fi HD, which lists for $99 and sells for less. Also highly regarded is American company Schiit (yes, it’s pronounced just how it looks), hence the punny name of their diminuitive Fulla, for just $79. They are one of those dangerous companies that draw you in with the quality of their lower end products, and you could end up spending $3,900 on the Ragnarok/Yggdrasil amp/DAC combo!

While several headphone manufacturers are getting into the game of insanely priced flagships for over $3,000, fortunately there are still some that are also doing a great job putting cumulative experience, knowledge and technology to great use in affordable options that far outperform most anything that was available even six years ago.


Headphoneus Supremus
Pros: refined, clear, detailed sound with fabulous bass quantity, quality and impact
Cons: non-detachable cables, limited availability, treble can be harsh for sensitive ears
 I am not an audiophile, I just like to enjoy music in good quality. This writing is more like a collection of subjective experience and impressions rather than a professional review. 
 Most of my music is different kind of EDM. (Amon Tobin, Vibrasphere, Shpongle, etc.) Deep and clean bass is important for me. My main headphones for 16 months was the X2. I preferred X2 to HD600 with my music, however I prefer HD600 to X2 for acoustic, classical music and vocal. X2s give the most bass as a dynamic opened pair of headphones. Bass might the most essential part of sound I am after, and it is indeed very difficult to find headphones with good bass. (Detailed, linear, extending to the lowest frequencies, clear, well-separated, and certainly not bleeding to the mids. And while it ticks all the mentioned boxes, it stays punchy, has a good slam, it is dynamic and powerful.)
 My dilemma I guess is one of the oldest dilemmas on Head-Fi. Opened back headphones will never give you that punchy bass with that extension and impact. Closed headphones on the other hand will never sound as natural and spacious as opened back headphones can. You must make compromise somewhere on the line. Better bass, or more space and naturalism.
I am yet to hear £5-600+ opened cans, but I did audition a good number of sub £5-600 opened and closed back headphones. I love my bass almost more than anything. But I equally like space and naturalness.
 X2 was a good compromise for a long time. Very competitive bass, while it keeps the space and naturalness of the opened design.
My X2s have eventually been dethroned by X00s. Do not stop here, if you would like to know, how.

 X00s are very well packed, in protective bubble wrap. The box otherwise is minimalist. Black cardboard box with a few details on it. There is a nice quality carrying pouch, but no carrying case. One 3.5mm adapter, and that is it. It is obvious, the creators of these headphones wanted to make this a ‘good value for money’ deal.  No fancy packaging, money went into sound quality. I personally prefer this kind of manufacturer attitude, a proper carrying case however could have been handy at times.

(No fancy box.)

Built quality:
 Built quality is superb, the headphones also feel very light. On paper there are lighter headphones, HD600 for example is 90 grams lighter. But the X00s also feel very light, maybe we just expect it to be heavier because of the wooden cups.
They never feel heavy on the head. Wooden cups are beautiful, magnesium alloy and other materials are good quality. Interestingly the colour differs a lot in natural light compared to the many studio photos you find online. In real life they look less orange, more brownish. Both colours are fantastic IMO, it was just interesting to discover the difference.

(Same headphones in natural and studio light.)

They are comfortable. Not the most comfortable, but comfortable enough. HD600, HE400s, Nighthawks, Fidelio X2 all are more comfortable. Not like you couldn’t wear X00s for extended times, you can. But you will never forget, you have headphones on your head. There is this “(good quality) headphones on my head” feeling, while with HD600 you can simply forget the weight.
I certainly can live with the comfort level of X00s, but better comfort does exist.

(Good pairing IMO.)

Space, soundstage: It is not the open air vastness and soundstage of HD600 or even X2, but we do have a very nice 3D space, which is fun and enjoyable. This was my biggest worry coming from X2s, whether I will miss the spaciousness of the opened back design. The 3D space X00s offer is really enjoyable. It is not the natural and airy sound of a good opened back pair, but they do give you a good space experience. (Kind of an arena feeling, instead of an open air field.)
 Losing some airiness is the smallest compromise you can make to enjoy the rest of the fun X00s offer.

Bass: For people who like bass as I do, and listen to similar music as I do, X00s are just bass heaven. There is everything, you need and you could ever wish for in bass. Extension to the lowest notes, with equal presence compared to other parts of the bass. You can’t throw a challenging enough track on them, that won’t give you the ultimate bass enjoyment. And it does it while the bass remains very clean and clear, well-separated, not bothering the mids. It also has a wonderful impact, punchiness and slam. This bass is much more refined and higher quality than M100, however quantity also leaves nothing to desire for.
Mids: Mids are more present than I expected. X00s have a more W-shape signature, not really V. Mids are also almost as much accentuated as the bass or highs. You hear everything that is happening in the mids. All the details in vocal, the smallest lip moves. But again, vocal will never sound as natural (lifelike) as it can with a good quality opened back headphone. It is still very enjoyable though, just in a different way. It is not lifelikeness or naturalness what you enjoy, but detail, resolution, presentation. It might not sound a good deal at first, but this actually is just a different way of having fun.
Treble: Very present, much more prominent than on X2s or Nighthawks. Also kicks harder, like everything else on X00s, and it has the same clarity and sparkle. I don’t think it is sibilant, but can be harsh a little bit. (Compared to X2, NH, or HD600, HE400s.). With burn-in this harshness seem to tame down a bit, but after 60-80 hrs I still find it a little more tiring to listen to than it was to NH or X2. It is not painful, and doesn’t even make you feel uncomfortable, but you know, you had music on your head for 2-3 hours, when you finish listening.

 Even though X2s sound airier, are more natural, have slightly better imaging and comfort, X00 just made me sell them. X00s offer much more than you lose. X2s sound like a pair of old speakers next to X00s.
(Plug with adapter is a bit bulky.)

  Final thoughts:
 X00s are definitely the most fun and most enjoyable pair of headphones I heard so far. To me they are just too addictive and enjoyable to go back to X2s, even though the long term listening sessions seem to give me a very slight fatigue. Anyway, at this point of my journey in headphone-land I really enjoy X00s, and I am very happy with this purchase.

 X00s are definitely a bargain for the money.
I use Chord Mojo, which is an amazing device itself. I think, Mojo helps X00s to sound more refined and detailed, with better separated bass.

  X00s are the best sound I found so far for my taste and music. I wish, treble was 10-15% softer, but until I find such a headphone, I can live with this extra 10% sharpness, as the sound is just absolutely amazing.

Update: I sold X00s due to my treble sensitivity. I find Nighthawk to be superior in everything else except bass. 
Very nice review. I am completely torn on whether or not I should get these and man, did you make the decision harder for me. I currently own a pair of HD600s and for a while now, I was looking forward to something else. Don't get more wrong, I love the HD600s and I appreciated and loved the great mids they have, but I would like to try something else too. This is where the THX00s come in, but I am super worried that the fact that they are less comfortable and have more recessed mids compared to the HD600s will prevent me from fully enjoying them. 
Could you maybe compare them a bit more to the HD600s (regarding their sound signature of course) ? 
Thanks for the excellent review, bestula.  My Purpleheart TH-X00's aren't due to arrive till August and I also have the X2's and HD540 to compare sound signatures.  Hopefully my observations will mirror yours.  Excuse me while I "hurry up and wait" for a few more months.
Whether you will like the X00s depends on your taste in music, sound signature and the purpose you buy it for. Only your own ears can tell you the final decision, however here are some more guidelines:
 X00s are not uncomfortable, they are comfortable enough to wear for hours. More comfortable than M100, Nad Viso, Momentum or similar headphones. However in my opinion they can't compete with the softness of HD600 velour pads, but the comfort level is good enough. It is not bothering in any way. (Only with larger than average ears X00 pads can feel too small.)
Another important thing is, with HD600 you must have a good amp/DAC to make it sound as it was intended to. X00s with their high efficiency will be fine with less expensive gear, however they still benefit from a good DAC.
 I think, it all comes down to your music preference. HD600s are the 'mid kings'. Vocal, acoustic music, orchestra is more natural, lifelike on them. Also the sound signature is very neutral, makes them good for studio monitoring. They do sound airier in comparison. For other music genres, especially modern music and EDM HD600s just unable to provide the bass you need. Lacks quantity, clarity and rolls off too early to hear that deep rumble, X00s can give. Highs are also more sparkly and have better extension on X00s than on HD600. Yes, mids are more laid back on X00s compared to HD600. (Pretty ,much on all other headphones.) But they are far less laid back than I expected, and again, it is not bothering at all. Mids are still there, they are clear and present. Just the spectacular bass department steals the show.
 After all I have just said, I was very surprised how X00s handled classical music. Actually sounded pretty good and very enjoyable. Clear and detailed, while giving you a great sense of 3D space. Absolutely liked it. Not as natural and lifelike as on HD600, but more detailed and clear.
 For any kind of EDM, modern music you will be much happier with X00s. If you are into classical or vocal oriented music, I would recommend HD600s with a good amp. I mostly listen to different EDM, so for me the choice is obvious. 


Member of the Trade: Acorn Audio
Pros: Incredible and far reaching bass. Punchy sound that gels with electronic and beat-heavy genres. Very comfortable and light.
Cons: Recessed mids. Sometimes strident highs. Non-removable cable. Only available when Massdrop wants with a long wait period. Doesn't come with a case.

When the TH-X00 first appeared on my radar last year, I had only a little knowledge of who Fostex were and their wide reach in the audio game. I saw Massdrop advertise the headphones as $399, marked down from $1000, and wondered what the quality must be. At the time, I was switching between a Sennheiser HD600 and a Beyerdynamic DT990 600 Ohm as my daily drivers, with more emphasis on the former.
About a half-year later, I finally have a pair in my possession. By this time, Massdrop is on their third run of the mahogany version and have just completed a run of the $450 Purpleheart version of the TH-X00. I’ve watched thousands being sold and people waiting anxiously as they shared their enthusiasm and impatience with others online. I daresay that the TH-X00 and the AKG K7xx are the most successful Massdrop collaborations thus far.
Specifications, from Massdrop:
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)
The TH-X00 is an impressive looking pair of headphones. The cups are a glossy pair of mahogany craftsmanship of which no two are alike due to natural wood grain. It’s a bit difficult to describe, but I get an “old-meets-new” vibe from the design. The wooden cups add an old-fashioned beauty and class to it, but the rest of the design is very much modern. The headpad is cushioned just to the point of necessity, leading it to look lean and smart while providing ample comfort. There’s no room for excess in the overall design, which results in its astonishingly light weight. Maybe I’ve just been using a ZMF Omni (in cherry too, one of the lightest) for too long, but the light weight, and therefore comfort, of these cans can itself be seen as a major selling point – especially given its sonic characteristics that I will discuss further on.
A major detraction comes in the form of an incredibly thick 10ft cable that isn’t detachable. I feel this design choice to be strange, given how much headphone-enthusiasts enjoy customizing their experiences with cables both standard and balanced. Due to how easy it is to drive, it would have been a comfortable and fun wear on trips and other situations that could call for portable use. This is all hampered by the cable. I’ve seen some modify theirs into a detachable version, but I feel Fostex should have themselves given this option given the TH-X00’s price tag. Interestingly, the Fostex TH610 that is supposedly based on the TH-X00 (and retails for around $750, pictured below) has detachable cables.
The cups themselves are well finished so that they gleam and look very inviting to onlookers, but aren't very rugged so care must be taken when handling these cans – which is a given to anyone who prizes their audio possessions but is still something worth mentioning. The lightness of the cups is very surprising as the other headphones I’ve used with wooden earcups (the ZMF Omni and Vibro Mk. I) have both been really heavy in comparison. On each cup there is a FOSTEX logo written in black, which is something I could have done without honestly. Unlike on the TH900, where the logo pops out on the silvered and candy-like red earcups, the logo on the TH-X00 looks dull by comparison.
The left side of the headphones has the Massdrop label printed on it while the right side has TH-X00 and the serial number of the pair written. The slide adjustment has two prongs and adjusts in small and satisfying increments – a far cry from the large bronze slider of the Fostex T50RP. The cups don’t rotate a large amount, but there is plenty of leeway for comfortable adjustment. These are meant to be closed cans, but the isolation isn’t the best. I would describe it as just adequate in that aspect. The clamp isn’t harsh at all so most of the seal comes from the rectangle/oval indents in the earpads. The earpads themselves are made from protein leather so vegans can rest easy purchasing these.
Overall, a very light and comfortable design that looks very premium and stylish. The only disadvantage being, to me, the logo on the outer cups and, to most, the non-detachable cable.
“Fun” headphones and tuning is such a subjective term honestly. Some in the audio game scoff at those who have Beats by Dre, but then at times themselves derive less pleasure than those whom they poke fun at simply because they are so caught up in the technical aspects of their gear to just sit back, relax and listen to some good music. If you are a listener who likes to be incredibly discerning of their listening experience to the point where it intrudes on the enjoyment of it, then these are not the headphones for you. That being said, these are the headphones those who enjoy Beats should have instead and this is why.
The bass on these is simply incredible for cans in the mid-fi range. The bass extends lower than my ZMF Omni, which held the sub-bass crown before the TH-X00 showed up. How it did this while being a dynamic driver instead of planar magnetic is a mystery to a guy like me – but it’s extremely impressive. It comfortably emitted bass frequencies that many headphones would struggle with.
A good example of this is in the song “Rap God” by Eminem, which utilizes sub-bass frequencies in its beat that would disappear on many headphones – or be very light and unsatisfying. The TH-X00 tears into it just fine and does so with ease. For the bass characteristic alone, these headphones are incredible for rap and electronic genres of music and they effectively beat the ZMF Omni for the low-end championship in my collection. It’s also quite fast, only falling short in this price range to the HE400i, which is planar magnetic. The HE400i has nowhere near the level of sub and mid bass however, but it is punchier.
The bass frequencies are quite disciplined but some genres can definitely show signs of bleeding into the mids – leading to too much bloom/boominess in the overall sound reproduction. This is especially apparent in classic rock where production methods were not as slick and advanced as they are nowadays. Led Zeppelin especially loses out in this regard, with the rhythm section feeling bogged down.
The mids are recessed, but not quite as much as I anticipated. I had read about this being a W-shaped pair of headphones rather than V-shaped, and I can see and hear that being the case. The sound is quite warm which especially stood out to me as my other experience with V-shaped headphones was the very cold and bright DT990. The lower-mids, male vocals and rap, are incredible clear and full and the trouble really begins in the upper-mids, female vocals and the like losing their body. A song like “Show Me the Meaning of Being Lonely” by the Backstreet Boys, which has many vocal layers stacking, has its overall impact lessened by the TH-X00. This is not unexpected however, given what the headphones try to achieve.
The highs can get a bit shrill at times, depending on what it is you are listening to genre-wise. Electropop with female vocals can especially be quite strident. Still, this aspect pales in comparison to the likes of the DT990 and makes for much more comfortable listening. The treble extends past the rolled-off nature of the ZMF Omni and HD600 with ease, which lends to a more impactful sound in snare-hits – giving the beat more “snap” to follow the intense kick that the bass reproduction provides. This further adds to the excellence of the TH-X00 for the likes of rap and electronic music.
Overall, the sound plays to the design that Fostex had in mind when it came to the TH-X00. They are simply the best I have heard to date when it comes to the genre-compatibility I praised above. They stumble at others but still sound quite good. There hasn’t been a point where I found anything problematic to the point that I would even characterize it as average.
Are you seriously asking? Why even read this section, just move on. You insist on knowing? Very well.
The soundstage is intimate, to say the least, even for a closed pair of headphones. Listen to ASMR or “3D” directional audio and you’ll hear just how the simulated world you knew before just got smaller – you went from a concert hall (if you have the HD800 or DT990) to a small room. I would describe this as the narrowest soundstage I’ve heard in full-sized headphones that I’ve owned in the last couple of years. It is narrower than even the ZMF Vibro Mk. I, which is also closed.
This shouldn’t even really be a consideration if you are looking into the TH-X00 as there are other headphones that can provide this but lack what these do offer however.
I have two amps at my disposal currently, the transparent Schiit Magni 2 and the slightly warm Cavalli Liquid Carbon. I found both, which are vastly different in price, to be more than sufficient in amping the TH-X00, which has an impedance of 25 ohms. You won’t be increasing the volume past a third of your amp’s capabilities and that will be louder than many can handle. Even my Galaxy S6 powered these adequately, which adds to the fact that the cables should have been removable so that a small and comfortable 3.5mm cable could have been used for portable devices.  
If you do manage to get a pair modified to do just that, a portable amp will do wonders for your sound. You won’t get good enough isolation to have a noise-free experience during a flight, but these sure as hell beat the standard headphones airlines offer.
Bass: TH-X00 > ZMF Omni > ZMF Vibro Mk. I > HE400i > DT990 > HD600
Mids: HD600 > ZMF Omni > HE400i > ZMF Vibro Mk. I > TH-X00 > DT990
Treble Quantity: DT990 > HE400i > TH-X00 > HD600 > ZMF Omni > ZMF Vibro Mk. I
Soundstage: DT990 > ZMF Omni > HD600 > HE400i > ZMF Vibro Mk. I > TH-X00
Comfort: DT990 > TH-X00 > HE400i > HD600 > ZMF Omni > ZMF Vibro Mk. I
Aesthetics: TH-X00 > ZMF Omni > ZMF Vibro Mk. I > HE400i > DT990 > HD600
Lightness: DT990 > TH-X00 > HD600 > HE400i > ZMF Vibro Mk. I > ZMF Omni
Ordering Process:
Obviously, as it’s a collaboration between Massdrop and Fostex, you can only buy these during one of the drops it’s placed on over at the website. As it so happens, at the time of writing this there are still 14 days remaining for the mahogany version. Sadly, the $399 does not get you a case. Only a dust-proof bag is provided in the box.
I'm still quite inexperienced with EQ so any feedback would be appreciated. I find the following settings on Foobar to make the TH-X00 retain its fun sound and bassy sound signature while taming the sibilance.
Here's a preset if you'd like to try it on your own Foobar2000 + TH-X00 setup.
When the smith-wizards over at Fostex made the prototype of the TH-X00, it asked what its purpose of existence was – sentient as all headphone prototypes are obviously. It was told that it was to entertain the masses, to whom bass quality resulted in increased enjoyment of modern music. That is, ultimately, what the TH-X00 was born to do. This is in no way the best mid-fi all-rounder, that crown still belongs to the Hifiman HE400i in my eyes, but it doesn’t offend while being stellar at its strengths. For $399, this is an easy purchase to make if you want an indulgent set of cans lying around for when you want a break from your high resolution and analytical system. It’s up to you if you want to wait several months for Massdrop to complete your order though.
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Song Impressions:
Equipment used: Foobar200 WASAPI Event > Schiit Wyrd > Schiit Gungnir USB Ver. 2 > Cavalli Liquid Carbon.
All tracks in lossless FLAC in at least 16/44.1
Abba - Gimme! Gimme! Gimme! (A Man After Midnight)
A lot more intimate than I’m used to, but with a far more pleasing lower end – which is very enjoyable due to its synth and bass guitar driven beat. The TH-X00 does especially well with the breakdown section, every bass note and slap rings out in the mix effortlessly.
Aerosmith – Dream On (2012 Remaster)
The TH-X00 does well with Steven Tyler’s voice. The rhythm section in the second half of the song does get a tiny bit congested however. Again, much narrower in soundstage than I’m used to.
a-ha – Take On Me
Now we’re talking. I haven’t heard this song sound as nicely as right now. It is delectable synthpop and the backing vocals are well represented.
Alan Parson’s Project – Sirius/Eye In The Sky (2005 SACD)
The TH-X00 adds a substantial amount of kick to the low end of these tracks, which kind of upset the delicate (and very well produced) balance of the instruments that I’m used to. The rhythm section of Sirius especially muffles the synth melodies a bit.
ATB – Too Soon (Feat. JanSoon)
The TH-X00 was made for tracks like this. It simply bumps.
B.B. King – The Thrill Is Gone
This is an interesting one. There is more mid-bass bloom than I’m used to but it works well with the track as a whole, with the bass guitar being a lot more pronounced in this blues classic.
Bee Gees – Stayin’ Alive
The TH-X00 actually adds to the disco attitude presented, although the vocal melodies don’t ring out as well as I know they can. Again, not an incredibly analytical pair of headphones but the tradeoff is that the beat has a lot more impact in both kick and snare.
Big Black – Kerosene
This song is pretty punk rock in production and attitude. Steve Albini’s voice transcends a noisy, jangly and treble-heavy wall of guitar sound in some of the most charismatic low-fi I’ve heard to date. What the TH-X00 brings to the experience is the more pronounced drum machine and drone bass, making it a fatter sounding song than it usually is.
Billy Idol – White Wedding
Just like a-ha, this song simply pops with the TH-X00. I think 80s synthpop/new wave production will generally sound really nice with these headphones. The production has more room in it for the low end to feel accentuated while not losing the detail.
Billy Idol – We Didn’t Start the Fire
This song is a lot catchier than I remember thanks to the TH-X00 with its driving beat. The higher vocal harmonies in the chorus feel subdued however.
Blink-182 – I Miss You
While the acoustic guitars don’t sound as lifelike as they do on my ZMF Omni, they do sound incredible and far closer to your ears than you previously knew. The mid-bass bloom doesn’t affect Tom’s verse so much due to his high pitched voice but does clash slightly with Mark’s lower register.
Blue Foundation – Eyes on Fire
I always liked the drums that come in later on in this track, and now I do so more. The impact and cinematic quality of them is breathtaking thanks to the Fostex.
Childish Gambino – Heartbeat
I feel like I finally understand the point of that harsh saw-bass riff that this song has because the low end that accompanies it is far more pronounced on the TH-X00 than any other pair of headphones I’ve ever owned. Very impressive. It does drown out the vocal harmonies and the vocal-ah synthesizer in the chorus however, but I’ll let it slide due to how immense the low end sounds. The guitar work in the second verse is, surprisingly, a lot more pronounced than I remember too.
Chris Isaak – Wicked Game
This is one of those songs that ranks amongst my top songs of all time and thus one I return to every time I have a new piece of audio gear. It has such a delicate and charismatic sound to it and I’m glad to say the TH-X00 does it justice in all aspects – emphasizing the bass-work while maintaining the delicate guitars and exuberant vocals.
Chromeo – Night By Night
Songs like this are purely enhanced by the TH-X00 with no detraction whatsoever.
Clint Mansell – Lux Aeterna
This haunting and cinematic piece feels more congested than usual, but still a nice listen.
Coil – Going Up
Coil’s last song feels even more haunting due to the increased droning mid-bass frequencies and the one vocal line being unaffected by it due to its high pitch.
Coldplay – Clocks
The TH-X00 does really well with this track and its driving beat. There is increased impact in the piano riff and driving bass/drum work. Chris Martin’s vocals don’t feel hampered due to the mid-bass bump.
Daichi Miura – Unlock
While the driving low end sounds sublime, I’m surprised by how sibilant the guy’s vocals sound compared to every headphone I’ve listened to this song on before. The reverb effect on the vocals feels less impressive than I remember too.
Darude – Sandstorm
Song name? Anyways, this early 2000s club banger does immensely well with the TH-X00, as expected due the electronic genre.
Ellie Goulding – Lights
She already has a thin and rather nasal voice in the upper register, but this makes it have even less body. However, the rest of the song is on point. Not sibilant however, interestingly.
Emerson, Lake & Palmer – From the Beginning
The acoustic guitar work feels a lot thinner than other headphones that I’ve owned, except the DT990. The body of the song comes from the low end again, but it isn’t how this track was originally structured to be. The bass guitar, as usual, is more audible however along with the synth solo that comes in later.
Eminem – Without Me
Another testament to just how incredible these headphones are with the genres they were meant for. The ebbing and throbbing bassline that makes the song sound so addictive has never sounded better to my ears. The treble extension makes the snare hit hard as well. A+ synergy.
Fleetwood Mac – Dreams
Songs like this struggle with the TH-X00 because of how the vocal and guitar centered they are. Even the bass guitar and instrumentation doesn’t sound as filling as it does on my ZMF Omni or the VE Monk Plus earbuds. A subpar match but still alright.
Kanye West – Jesus Walks
Very addictive bass thump but less controlled than on the HE400i. It feels looser.
Kavinsky – Nightcall
Enhances the song in every way except the female vocals, which sound a bit thinner and slightly sibilant. Sounds, overall, more brash and bombastic - as it should due to its cinematic nature.
KMFDM – Megalomaniac
Industrial music you can dance and headbang to. The bassline sounds a lot more club-like than what I heard previously. The guitars also sound filling, lending to the overall sound having more immediacy and impact.
Korn – Falling Away from Me
This is a song that I was absolutely sure would feel extremely stuffy with the TH-X00 due to how it is mixed, but the headphones surprised me with their perseverance…to an extent. Still really boomy but enjoyable.
Lana Del Ray – Summertime Sadness
This mournful ballad feels simultaneously more and less “cinematic” in presentation with the TH-X00, which add a drive to the slow and measured drum-beat but take away from the swirling string section that accompany Lana’s incredible studio voice – which itself is represented well in comparison to most female vocals. Overall, I don’t prefer it over other headphones I’ve heard but it’s still a good match.
Led Zeppelin – Achilles’ Last Stand
A bit of a mismatch here, with the TH-X00’s emphasis on the low end drowning out Page’s guitar work substantially – which is a no-go for Zeppelin listening. The drums and bass are a bit overpowering. Plant’s vocals survive however.
Linkin Park – Breaking the Habit
The clean and electronic-sounding production of this track are benefitted from the audition of the TH-X00 largely but there’s a sibilant nature to the processed vocals now.
Lorde – Royals
The bass and drums steps into Lorde’s main and backing vocals substantially, but the overall listen is still quite stellar.
Machine Head – Davidian
The strong yet undisciplined low-end power that the TH-X00 pulls out of this track is extremely impressive. The guitars sound as heavy and distorted as they should while the incredible drumwork gets its absolute due thanks to the sound signature.
M83 – Midnight City
This song mixes shoegazing elements with electronica/house. Interestingly, the TH-X00 gives it more structure due to the beat and bass being more pronounced, while some headphones loses this aspect to the huge wall-of-sound that the production has. Very enjoyable listen that handles the atmosphere well.
Martin Garrix – Animals
If you had to use just a single track to convince a basshead why they should buy the TH-X00, this is the track you would show them if you want the best result. The sub-bass in the rise and drop is just ruthlessly massive and breathtakingly deep. 
New Radicals – You Get What You Give
This song is a good representation of what I meant in my video regarding how the TH-X00 doesn’t sound as “natural” as some other headphones that I’ve owned. A large amount of the packed instrumentation that this 90s classic has is reduced by the Fostex to sound more linear and with more emphasis on the beat and vocals. The piano is quite lost in the mix.
Nirvana – Smells Like Teen Spirit
I daresay that you’ve all heard this song before. The guitars sound a tad recessed but still very “dirty” and grungy (pun intended) while Dave Grohl’s drums take center-stage along with the simple driving bassline. Cobain’s tortured vocal maintains sufficient body to command the attention it deserves and has always deserved. The TH-X00 delivers.
Pendulum – Set Me on Fire
Just like the Martin Garrix song, the drop in this is exactly what the TH-X00 was designed for. The headphones do extremely well with the chaotic drop and dish out all the detail necessary for its enjoyment. The 90s-video-game-like synth that follows is also done justice as it isn’t muffled by the bass frequencies. Again, a song that I haven’t heard sound this good on other cans I’ve had.
Queen – Bohemian Rhapsody
The ahead-of-its-time production really does well on the TH-X00. Even the famous bridge section with the stacked vocals falls right in the region that the headphones is rendered admirably. The closeness of the vocal layering provided a new experience to my ears over the other cans I’ve had. I heard more detail, ironically, due to how close it was. Overall a good match of song and headphone.
Queen – Another One Bites the Dust
Alright, this has to be heard to be believed. It hasn’t sounded punchier and more aggressive before, before. Extremely good synergy. All the instrumentation and vocals fall squarely in the regions that the Fostex excel in.
Rage Against the Machine – Killing in the Name of (2012 20th Anniversary Edition Remaster)
Another great pairing. The TH-X00 gladly joins in the attitude the band exhibits with Tom Morello’s guitar overdubs sounding just where they should on top of the driving low end.
Ramin Djawadi – Game of Thrones Theme Song
While the low end instruments sound satisfying, a lot of the upper-mid detail is quite recessed. The main melody feels drowned out by the thunderous percussion section. A lot of nuance is lost, but that was to be expected given what these headphones were designed to be.
Slipknot – Wait and Bleed
The warm and powerful sound signature lends greatly to this relentlessly aggressive track. A lot of the extra percussive elements (Slipknot has two percussionists along with their drummer) ring out in the mix. Some of the cymbal hits can be quite sibilant however.
The Glitch Mob – We Can Make the World Stop
Another good pairing, but don’t turn it up too much because a lot of percussion and “glitch-breaks” can be quite sibilant. The low end is simply stellar however.
The Weeknd – The Hills
Sub-bass galore. The snare is a little piercing but it’s easily forgiven for how much the TH-X00 brings out in this song. The sparse production prevents any drowning out of instrumentation too.
Zack Hemsey – Mind Heist
This low-end driven “epic” orchestral piece is served well the TH-X00 to add to its power. A lot of nuance in the percussion is reduced but the tradeoff is immense power when the song fully builds up.
@musikaladin Yeah, I didn't know much about Fostex back in November but then I got the ZMF Vibro in February and then the ZMF Omni in April. I know they're Fostex T50RP mods.
I asked a while back about a set of headphones specifically for heavy metal and rock. I found my HD-600's to be weak for that genre. These were suggested and they are indeed just what the doctor ordered. If you have HD-600's and want to experience its alter ego get these.
Great Review, thanks for all the time you spent on it and the description of each song,
I own the 400i but at work, i need something that gives me more isolation, might be my next purchase.


500+ Head-Fier
Pros: Stunning bass, attractive design. Scales well. Puts the fun back in music.
Cons: Comfort a bit lacking, cannot change the cable, 1/4 inch jack
Seeing as the TH-X00 is going through it's second drop on Massdrop, and will be close to selling out by the time I press "Submit", I thought I'd write a review to try and explain what all the craziness is about.  
The TH-X00 are a exclusive headphone designed by Fostex for Massdrop.  You cannot purchase these headphones anywhere but from Massdrop, and currently there are only 2000 of these headphones in existence, and as of May of 2016, 1000 additional copies will exist.  So scarcity helps build the hype around these gorgeous natural mahogany cupped semi-closed cans.  On the other hand, there wouldn't be any hype or discussion at all if the TH-X00 sounded like garbage.  
I picked up a pair of these after reading a rave Head-Fi review about the amazing bass response these headphones achieve-- and then the "must act now" and "exclusive" language kickstarted what I call my "Big Dumb Guy" (BDG) gene and I just HAD to have them.  Right?!  I got serial number 1166.  That BDG gene has cost me tens of thousands.
On the face of it, other than the beautiful mahogany, they're fairly ordinary headphones.  The pads are pleather and they're a bit cramped, the cable cannot be replaced without a solder job, you have to use a ridiculous 1/4 inch step-down jack to use them with an iPhone or Astell & Kern player or laptop, and the case is just a basic bag.  That-- is where ordinary stops.  Plug them into any reasonably decent source, and you're in for a ride.  Plug them into a great source, and you're going to hear something very special.
The TH-X00 are insanely efficient.  At just 32 ohms they're compatible with any source you can find, which is why the 1/4 inch jack makes no sense.  No matter.  I'm pairing them with the AK240 and Chord Hugo... yep... $3500+ in source gear for a $400 headphone.  Trust me, it's worth every penny.  These cans scale extremely well with the source.
Because the speaker tech is trickle down from the basshead Fostex TH-900 and TH-600, you would expect a lot of bass, and these don't disappoint.  Where the TH-X00 jumps ahead (in my opinion) is they tightened up the bass and removed most of the bloat that often muddies the lower frequencies.  Yeah, there's still a little bloat, but it makes the headphone fun-- it has swagger.  I love headphones with an attitude.  The bass is rich, deep, and powerful (even explosive at times), without losing too much definition as basshead cans tend to do.  This was a tuning choice by Massdrop, and I think a wise one.  Where the TH-X00 falls behind the upper price range cans (say, the Audeze LCD-3) is bass speed.  But just the fact that it's worth comparing the bass to any LCD, at just $400 dollars, it says a lot about how good the bass is on the TH-X00.
The highs are open, but not extended.  At first listen, I thought the highs were muted and I was almost disappointed.  But putting on Supertramp's COTC-- "Dreamer" the triangles ring very clean and clear-- the harp on the beginning of "School" is crisp and even airy-- but without a lot of brightness or sparkle that sub-$500 dollar headphones amp up in the name of "fidelity".  It's a very unique sound-- because it gives the headphone a slightly dark signature like more expensive models, but you're getting the full frequency range.  
Soundstage is better than you might expect, and I'm guessing this is because the design is only semi-closed.  It's no HD-650, but there's enough width to give you a nice presentation and there's above average imaging and definition, too.  
So where does this headphone fit?  I have no problem calling it the best $400 dollar headphone on the market.  In fact, I think it's the best sub-$500 dollar headphone out there.  I also own a Bowers & Wilkins P7-- which I place well ahead of the famed Sennheiser Momentums, and I seriously looked at the HiFiMan HE-400S-- which is a bargain at $300.  But the TH-X00 sounds like a $1000 to $1200 dollar headphone to me (maybe higher), and given its scarcity, it's easy to see how nearly 700 of the 1000 units in the SECOND drop have been claimed in just 18 hours.  My P7's have been gathering dust since November.
My usage-- They're a bit bulky, but I bought a travel case and I take them with me to work on days when I know I have paperwork and on the road when I travel.   I took them on a recent flight to Dallas-- despite the semi-open design, very little sound leak on an airplane, my neighbor didn't complain at all.  Paired with the AK and Hugo-- I'm getting hammer of the gods for in-flight entertainment.  These cans are addictive.  
I don't use them much at home, mostly because I have the HE-1000 which get nearly all of the listening time.  But if I'm in the mood for lower level listening-- I will reach for them.  The other point I'd make is this:  They're fun headphones.  They're not analytic.  I'm not doing reference-level listening, I'm kicking back and enjoying music.  With the HEK, I find myself searching for tracks that show off what the headphone can achieve (which, to be fair-- is reason enough for owning them-- they're my favorite headphone on the planet at the moment).  With the TH-X00, I'm able to let go of the technical prowess and rock out.
If you're lucky to pick up one of the remaining 300 in this latest drop, you're in for a heck of a ride.  
UPDATE:  Massdrop has just released a variation on the TH-X00 in Purpleheart wood.  I did BDG it again, and picked them up.  They don't arrive until August of 2016, but I'm such a fan of the original, I can hardly wait to hear the improvements.
At CanJam LA 2016 I had the opportunity of A/B listening with the Fostex TH900.  The biggest difference is detail.  The TH900 were articulate during complex passages, the TH-X00 sort of glossed over those passages.  So for $1000 bucks you add detail, a bit more flash on the cup, removable wires, and an arguably more complete sound.  That's not to diminish the TH-X00.  It's still a terrific everyday headphone, and I brought them to CanJam to let my friends have a listen as I went from vendor to vendor-- I never heard a bad word about them.  
Nice review. I pulled the trigger on the drop a couple of hours ago. Can hardly wait until they com in in May. Your review makes me want them even more...
The Third
The Third
Too much talk about numbers and prices to be honest. I also doubt these will be better than my HE-400 (original), as semi-closed dynamic drivers are very likely to be slower and less accurate. I am in the second drop, though I won't be opening the box up until I see some professional reviews coming in. I respect Jude and his followers but after seeing how his whole review seemed like a commercial stunt; it's also linked on the X00's Massdrop page. I seriously doubt these cans come close to the HE-400i aswell...
If you can't find anything nice to say...


Headphoneus Supremus
Pros: Excellent Value, Unique, Great Recommendation For New Headphone Hobbyists, Bass, Mahogany Cups
Cons: Some congestion/speed issues, 9' cable, have to wait for drops to buy or buy used,
Value - 10/10
Audio Quality - 9/10
Design - 8/10
Comfort - 8/10
35 out of 40 final score. A solid B+ rating for me.

What shows up in the review page is an average of what users have rated these phones, even though it looks like it's my rating alone.
First let me start by saying thanks to Will at Massdrop for sending a review unit, not just for review but for the Seattle meet we had recently on Dec 6th, 2015. As this is a review unit, I have promised to write an honest review which allows me to keep the headphones a tad bit longer until my actual purchased unit comes in. This was a record breaking drop over at Massdrop with ~1000 units selling in 3 hours and over ~1400 on the first day. Rightfully so as this headphone offers massive value over yesteryear’s TH600/900 releases.
Many have gone over the construction of this headphone so I will just say that the construction and quality is similar, if not identical, to the Denon D2000/5000 and Fostex TH600/900, not counting the Japanese wood used on the 900s. The mahogany wood really creates a beauty to these and the finish is fantastic. The black on wood scheme also makes the wood color pop, tastefully put together for the eyes and makes for a great show on a headphone stand.
The headphone is fitted with a non-removable 9-10ft quality cable with a 6.3mm (1/4”) termination. Rubbing the cable to my jacket zipper, I get 0 cable noise to the phones. The feel is silky smooth and looks is fantastic. There doesn’t seem to be a need to put audiophile rope vines on these but time will tell if it holds up to use. The cable could have been shorter at 6’ to allow some portability but the longer length works perfect for home and office use. With the headphone came a synthetic leather pouch, good on keeping scratches at bay but offering 0 impact protection. I highly suggest getting something like a Beyerdynamic padded soft case or a hard case.
Reviews are based on 1st and 2nd chain as source:

1st chain:
Lossless Files > PC w/ Foobar 2000 player > Gustard U12 transport > Schiit Bifrost Multi-bit > Project Horizon 3 Hybrid Tube/Mosfet Class A Amp (1.5ohm output) > Fostex/Massdrop TXH00

2nd chain: portable
Lossless Files > FiiO X5 Gen 1 DAP > Cayin C5 Amp > THX00

3rd chain: ultra-portable
Lossless Files > FiiO X5 DAP > THX00 or Lossless Files > Ibasso DX50 > THX00
The THX00 actually sounds decent out of the FiiO X5 alone, which is surprising because the X5 has a weak and colored amp built-in. The synergy is fantastic which creates a very addicting fun sound.
Straight to the good stuff:*
The THX00 has a warm signature that can be a comfortable listen for hours, they’re fun sounding which means to audiophiles there will be a bass boost with slightly subdued highs.* Before you get discouraged, please read on and know that this headphone was well regarded by many who have been into headphones for some time. I’ve gone through my fair share and these have a special niche in my line of neutral/reference phones mostly tuned for accuracy.
Let’s start with the bass:* I believe many buyers will go for these just for its bass characteristics. The bass is tuned to have prominent presence without encroaching the mids and highs. This is something special as it gives the headphone a lot of emotion/feeling with a healthy bottom end. The sub-bass, when called upon, can really shake your noggin; music like rap, r&b, electronic and all of its many branches absolutely shine on these. The sub-bass in the 50-60hz region has a very good thump and extension as well as the ability to sustain the bass for extend periods, this makes the headphone not only great for certain genres but also great for TV and movie use where the sub-bass region is heavily used/boosted. The 100-200hz has only a very slight boost, which allows the phones to be more flexible in different genres. With genres like jazz and vocals, the bass doesn’t encroach or overpower the mids or highs which is particularly important in allowing other genres that require a more neutral sound to be played without sounding too colored. However to someone like me that particularly enjoys the bass line making the backbone to a band’s sound, it really reveals this region quite well and thus gives the phones that emotion.
The mids:*
This is where Fostex/Massdrop seem to have gotten this phone to be a niche in the midst of the Denon and older Denon TH variants. The mids are not V-shaped like it’s predecessors, a half or quarter step back for mids but nothing like the TH600/900 or Denon D2K/D5K. The mids have a nice silky smooth sound you’d expect from a bio-cellulose diaphragm, something I’m used to hearing from Sony and their house sound where the mids are liquid and refined. Unlike its predecessors, the THX00 mids are not hiding behind the bass or treble and is not a sacrifice to create substantial bass and airy highs. The vocals are well present here both male and female, as well as instruments that rely on this region to sound full.
The highs:*
The highs on the THX00 is tuned for long listening sessions, somewhat subdued but not overly to where the highs are an afterthought. More importantly the highs and mids are more even keel than previous Foster models, somewhat catering to the owners who complain about the V-shaped sound on previous models. While it does extend quite well, it lacks air and and openess of say something like the Beyer T70 or AKG K612 Pro (complimentary phones to the THX00 btw).

Essentially these headphones bridge a gap between the audiophile world and the consumer world. And it does so in more ways than one. First, it allows newcomers to the hobby moving up from sub $100 phones including the big B with possibly less than ideal source like a cell phone. These phones are the perfect recommendation for someone still appreciating the consumer sound of, "is there bass" and using Pandora/Spotify; but at the same time audiophiles or properly geared headphones listeners can appreciate the well done, fun sound the THX00 creates, something that requires grace and a fine line to balance. However, this phone isn't a do-it-all nor is it an audiophile's main phone. Consider it an exotic mistress to your truthful reference collection. If you've got a few of those already in your collection, this may be a bit redundant although a nice addition to any collection.
*Delivery and late but important thoughts after burn-in: (the reason for the * in the frequency breakdown above)
Out of the box the THX00 can sound closed in with the bass boomy to some, this in turn effects the clarity on the mids and highs. Something I noticed while A/Bing between the THX00 and Denon D5000 at the Seattle meet. I didn’t realize this until having the headphone for a several weeks now (over 200hrs of music plus 70hrs of LOUD electronic music - a must) but proper burn-in is huge in sound changes and settling of the drivers. I can say today the headphone is quite different from when I first got it and unfortunately when I wrote the frequency breakdown on this thread. I may re-write that section fully and amend this review but until then, the write up above are more initial impressions even after 150-200hrs of music. This headphone after a long burn-in process now sounds more of its kin in the Denon and TH6/9 series. The decay is faster and more controlled on the bass, the highs a bit more clarity, but adversely the mids are now a little pushed back. Not quite as drastic as the Denon D2000 or D5000 but now the lows and highs have stepped forward where as previously things seemed even with an big bass. In turn the clarity and separation is now there, which was my biggest issue albeit worth looking over for that extra fun. I’ve put about 200 hours into the headphone at 70db (which some would think is a bit on a soft side) but it wasn’t until the LOUD 90-110db electronic music piping through did this newfound sound come about. I would highly recommend that after 48hrs of regular listening that you run another 48-72hours of electronic music or white noise to properly break these in.

Where as before I would not recommend this headphone for symphony or heavy guitar rock music due to instrument separation being a problem, now I can easily recommend it as a do-it-all as well as specialized phone. The THx00 is still not my first choice for symphony and classical but much better than my initial thoughts.


Conclusion and notable mentions:
For the price these are a no brainer, an excellent way to get into the Fostex sound. As it is now after burn-in, I believe these may be a bit redundant for current TH600/900 owners as well as the older Denon owners with too many similarities. On the flip side, if you've been looking at those phones and wondering if the price tag is worth it, well here's your excuse to get one. If you’ve got an HD650 and other mid-tier phones, this should still be in your radar as it is unique and provides an excellent closed back alternative. Of course if you want a woody (who doesn't) then these should definitely be on your radar. Massdrop and Fostex has done something special with the THX00 and gets my high recommendation. They are not however an end-game phone (for me), although many who choose to spend less than $500 on phones may find it to be a halting point in the hobby and go off into the content sunset.
Notable Mentions:
- These have outstanding value and does not play into the diminishing return side of the hobby.
- The Mahogany cups vary in texture, some being absolutely breathtaking in pattern and cut, some being somewhat dull and plain.
- The build of the headphone is fantastic; time will tell how well they hold up to daily use with possibly the cable being the weakest link.
- A bit too flashy for public use but they isolate well enough to enjoy a cup of tea or coffee at a public place.
- The pads need time to wear-in, initially they can get uncomfortable after an hour of use.
- Doesn't take much of an amp to drive these well, for newcomers a cell phone may be enough to be content until better gear is acquired.
- BURN IN IS REAL! 48-72hrs of 70db music then follow it with another 72hrs of 90-110db white noise or electronic music, away in drawer.
I just got mine today.  Trying to figure these headphones out.  Clearly the nicest headphones I've had but I think I need to get used to the sound.  Lots of separation - can hear everything clearly... vocals are in your face and can hurt your head as you turn up the volume.  I am assuming that is what is meant above in the comments by someone about mids not being recessed.  I'm using a C421amp from JDS labs and have the bass boost permanently on which isn't the case with my Fischer FA-011's.  So these aren't as bassy as the Fischer's or the Monster Turbine Copper IEM's I have.  I also have the Denon AHD2000's.  They are similar to these which others have mentioned.
Curious for us headbangers that like to feel our music pulsing through our bodies - the nicer the headphone, the less need to turn it up?  I'm curious anyone's opinion relative to the transition to nicer equipment.  I typically like it turned way up....
You may want to run music through them for a bit, they started the way you explain the mids but they do change over time. If the volume is too loud to where it hurts, turn it down or let the phones bUrn - in first.

Also be sure to check into the thx00 thread for more info/opinions.
Hello, I have the Fostex TH-X00 and Grace Design for 3 months. I have about 150-200hours of using (music/burn in) It change every day by a bit. And one day (about 50-70hours of using) when I back from work and I put headphones on my head. I noticed huge inprovements than before. Everything was more detailed, clearer, very natural, rich, bass was absolutely huge and nice. It was AMAZING experience (This experience was  with my smartphone Samsung Galaxy S5), I loved this headphones, unfortunately but next day, this headphones sound worse as the first day when I purchase. After few weeks I got Grace Design m9xx Amp/Dac. But it change SQ by a little, little bit. Do you have any ideas ? Maybe I burned- in not  by much. Can you give me properly burn in instructions with my Amp/Dac.?


Headphoneus Supremus
Pros: Sub Bass, Mid bass, lower mids, forward presentation, smooth, soundstage for closed headphone, good detail, warm, fun, smooth energetic treble
Cons: imaging accuracy, upper midrange/lower treble are a bit wonky, non-detachable 10 foot cable
Intro - Context for the purchase (Read this if you want to understand where I am coming from when relating to this headphone.  I like to create a narrative to my reviews, but strictly speaking this portion isn't actually about the headphone, but rather helping to understand my frame of reference).  
This hobby can make people do strange things, well, besides sinking hundreds (errr thousands) of dollars into it.  As I was coming up in the world of headphone audio, my first three headphones were the AudioTechnica AD700, Grado SR60i and Denon AH-D1001.  I liked the trio a lot, and I own and enjoy all of them still except the SR60i (I have an SR80e now).  These were my gateway drugs, and they also helped inform what I was after in a headphone.  While I thought the AD700 was the best of the three overall, the one I found myself listening to the most often was the D1001.
The D1001 was closed, easy to drive, portable, comfortable, and it had this V shaped sound signature I loved, with punchy mid-bass, yet clear present vocals.  As I “moved up” I eventually reached the pinnacle of that sound, staying within the Denon (made by Fostex) line, with the D7000.  
The D7000 was a revelation for me.  Having saved cash and also selling my AudioTechnica M50 to get it, it was everything I wanted at the time.  I bought it used for $650 (it was, at the time, a $1000 headphone new, and $650 was a steal for it, probably because it had been re-terminated with a 3.5mm end, which at the time was an admission of having an inferior rig).  I loved it.  I loved everything about it.  I loved the look, I found the powerful U shape of the signature intoxicating. The soundstage was better than everything I had heard except the AD700. The smoothness was intoxicating.  I could have probably kept that headphone and been happy for the rest of my life.  It was a huge investment for a kid spending his first real job paycheck (that should have gone to other bills) straight out of college.  
But, like a lot of people here, I kept reading Head-Fi.  The D7000, while generally praised, wasn’t considered a “serious” headphone.  It wasn’t “reference” and people who liked non-reference headphones were morally deficient, or something.  They weren’t being “true to the artist’s vision” or were showing off their commoner, unrefined tastes.  It was fine to maybe own a D7000 as a side headphone to your main, proper, setup, but to have it be your primary was something of an embarrassment.  
So, I sold the D7000, saved some more cash, and bought my first “real reference” setup.  A Sennheiser HD650, a bifrost DAC and a Darkvoice OTL tube amp.  Eventually I would sell the Darkvoice and get a Schiit Lyr.  
Now, I liked the HD650, and I don’t really regret the move, but I ALWAYS missed the D7000.  I still owned the D1001, which could provide some of the fun, but nowhere even close to the refinement, and pure sense of joy the D7000 gave me.  I have owned, and sold a decent amount of gear over the years, and the D7000 is the only headphone I’d ever missed.  
Over the years, D7000s became even harder to come by, as Denon stopped contracting Foster/Fostex to make their headphones.  There was the Fostex TH series, but they were expensive, and not exactly the D7000 either.  
My first usage of Massdrop was the Grace m9XX.  I love that thing.  I couldn’t believe that a product like that, that frankly blew away setups I had owned costing 4 times as much, was that good, that affordable and that well done.  Then I saw Jude’s post announcing the THX00.
This seemed like as close as I was going to get to a D7000 without scouring classifieds and hoping that I got a lightly used and/or well taken care of used pair.  And they were priced at $399. Realistically, I had little expectation that they would be exactly as good as the D7000 was.  The D7000 was over $1000 when it came out in the early 2000s.  But if they came reasonably close I’d be happy, especially given the price.
At first though, I kinda balked.  I had just spent $299 on the HiFiMan HE400i, and $499 on the Grace m9XX.  These weren’t in my budget.  I already owned Shure SRH840s that I was very happy with.  I also didn’t love the idea of a 10 foot cord with a 1/4” termination.  At this point I have committed myself to every headphone I own being drivable from an iPhone and at least portable enough to walk around my house with.  However, the allure of getting something like my beloved D7000 back won out.  I could afford it, even if it wasn’t strictly in the budget, and a re-cable isn’t the hardest thing in the world, right guys? Sure, yeah, it’s a DEAL, right?  How can you say no at that price?  I couldn’t.  
Turns out a lot of others couldn’t say no either.  The drop, I believe Massdrop’s largest to date at 2000 units, sold out 8 days before the scheduled end date.  I actually received my headphones before they were originally scheduled to ship out in the first place.  
Unboxing was a bit underwhelming, Massdrop pulled out no stops, there was a 1/4” to 3.5mm converter in the packaging box, not even the product box.  The product box was as plain black and white as possible.  The packaging material was simply cleverly folded cardboard.  There was the headphone and a pleather Fostex bag, and that was it.  But it was understandable, This was a clear attempt to do everything they could to give us as quality of a headphone as possible, at as cheap of a price as possible.  Not having to impress buyers on a shelf, they could punt on the packaging.  One quick word about the bag, turn it inside out and it makes for a great cleaning cloth for the headphone’s gloss finish.  It’s got some sort of microfiber lining that gives a really nice buff to the finish.  The included adapter isn’t very great, and if you’re going to use it more than occasionally, I’d suggest replacing it with a much better Sennheiser or Grado adapter.  I would also highly suggest when putting your headphones in the bag, put the cable on the outside and use the excess string from the cinch chord to tie around and secure the cable.  This will prevent the large metal 1/4” plug from banging into the cups and potentially messing up the finish on the pretty wood cups.
About those wood cups.  They’re gorgeous.  I think the finish was very tastefully applied to let the mahogany really show.  With the TH900, the look is all about the finish.  From a glance they aren’t even recognizable as wood.  With the THX00, it’s all about the wood.  Depending on the angle of the light, they can totally change appearance, from a light blonde to a caramel color to a dark amber to a rich brown.  Often times different parts of the grain will simultaneously exhibit multiple of these.  They almost have a 3-D look to the finish due to this.
The pleather (whatever an eggshell protein is) pads are fairly massive, characterized by two large humps in the front and the back.  The padding is soft to the touch, but supported underneath.  They’re certainly not hard, but they’re not a floppy pillow either.  The band is similar.  There’s no padding, but due to the cup design and the even distribution on the headband, I literally can’t feel it on my head.  If you have a “sharper” shape to the top of your head (ie something like a less extreme conehead) you may not find these comfortable, but for me, the headband is shockingly comfortable given that it has 0 padding.  The connections between the band and the cups are magnesium. I’ve seen people call this cheap plastic, no, it’s magnesium, which is metal, they didn’t seem to take a shortcut in build quality at all.  As far as I can tell the only plastic on the entire assembly is the ring that the earpads attach to.  
The cable… Well, the cable is what it is, some people will love it, some will tolerate it and some will hate it.  It’s not detachable.  No Fostex headphone has ever had a detachable cable as far as I am aware.  Because of this Fostex didn’t even have the ability to manufacture a detachable cable without retooling part of their factory, which would have added a couple of hundred dollars to the price.  Yeah, I’d prefer a detachable cable, but not if it raised the price to over $500.  It’s long, 10 feet.  It has a nice 1/4” termination.  It’s immediately similar to what I remember of my old Denon D7000, it may even be the exact same.  As soon as I’m done traveling, I plan on sending mine off to have the cable cut down to 4.5 feet and reterminated to 3.5mm.  I then plan on having the excess cut off end keep the 1/4” termination, and add a 3.5mm female jack, essentially making the leftover 5.5 feet into an extension cable that converts the 3.5mm to 1/4”.  This will allow me to go from a can that can be portable to a home/office sit down listener easily.  The nylon sheath on it is nice and the cable doesn’t tangle or kink easily.  It’s a good quality cable, its just non-detachable, 10 feet long and has a 1/4” termination.  If that’s the cable you want, you’re in luck, if not you’ll have to have recabling (or in my case just modification) done.
A bit about pads.  A lot of people have already obsessively been trading various pads out with these, in order to ‘fix” various issues those users have with the pads.  Some wanted leather.  Some wanted a more spacious cup housing. Some wanted to change the sound signature.  I like the presentation that the stock pads give, so I haven’t done that.  I’ll probably at some point experiment with the Brainwaves lambskin pads, but for this review they were stock.  I personally like them.  Note however, that the pads rotate.  Experiment a lot with rotating them, because they substantially improved a noticeable amount when I got mine rotated *just* right for my ears.  Soundstage, bass impact and clarity all improved and comfort drastically so, in contrast to the way they felt straight out of the box.  I guess I have slightly asymmetrical ears, because my left pad was rotated slightly more counterclockwise than the right was.  
Amp Pairings:
Now, finally, on to the sound.  Well, almost.  Before I go on, I want to talk a bit about amp pairings with this, what I tried, what I settled on as being best for it, so that it’s clear what all my sound impressions following will be based on.  At least this is related to the sound, if it’s not actually a description of the sound.
The THX00 is a very efficient headphone, an iPhone can get it very loud without even coming close to maxing out the iPhone’s volume control.  I can’t even touch it to my ears with my iPhone on max volume.  In some ways of thinking, that makes it an easy headphone to amp, and some may even say it doesn’t need an amp at all.  
There’s long been this idea on head-fi that amp pairing is some sort of voodoo, or that the only way to get a good “synergistic” pairing is blind trial and error.  I remember when I first joined, lots of people paired AKG K701s with DarkVoice OTL tube amps that had like 32 ohm output impedance.  Nobody really understood damping and how low impedance headphones usually needed lots of current.  The introduction of the O2 changed a lot of that.  
The THX00 is a very current hungry headphone.  This is the most important thing to understand when deciding on an amp pairing.  It’s not going to sound good at all out of an OTL tube amp with high output impedance.  In fact, it would probably sound better out of your iPhone in that case.  Our friend Ohm’s law says that for any given voltage, current rises as output impedance goes down. So, since the THX00 is current hungry, it’s important that you amp it with something with low output impedance.  The original Vali (which didn’t have a gain switch) sounded pretty mediocre to bad with the THX00, as it was a hybrid amp with almost 6 ohm output impedance.  The O2 sounded much better, with its sub 1 output impedance.  The Grace m9XX sounded best, in my opinion, of anything I tried it with, not surprising given the Grace’s 0.08 ohm output impedance.  
I think it also pairs best with Class A amps, or at the very least class A/B amps with a high degree measure.  I don't want to go into the finer details of class A vs Class A/B, but essentially it comes down to class A has "current on demand" whereas Class A/B, due to its switching nature, can be a bit more sluggish in delivering its current to the headphone.  Some Class A/B amps, this isn't really as big of an issue, as they are "on" for almost the entirety of the 360 degree cycle, whereas some are off for half of it.  Regardless though, Class A is the gold standard here.
I didn’t like tubes with it.  I think the THX00 often straddles the line with bass control, and tubes really didn’t help that at all.  Especially since most tube amps are higher output impedance anyway.  To me a good, linear solid state amp with as low of output impedance as possible is what you want driving these.  The bass quality improves dramatically, most of the bloat that some reviewers noting going completely away, the bass texture dramatically improving, and the smoothness of the treble improving as well.  I think the THX00 sounds pretty great straight out of an iPhone, but the *right* amp (not necessarily the most expensive or powerful amp) takes it to a higher level of refinement.  While the THX00 isn’t particularly “difficult” to amp, at least in the way that the HiFiMan HE6 is hard to amp, it is very amp picky.  anything with over 4 ohms of output impedance and the bass is immediately, very obviously noticeably flabby. Usually my AudioEngine D1 plays well with low impedance headphones even though it’s 10 Ohms.  Not here, it became a bloat monster.  Sometimes in a fun way, but a bloat monster none the less.  The Vali sounded bad.  My old Starving Student Hybrid was laughably bloated, the bass just going all kinds of ways and becoming overwhelming.  The Grace m9XX, Magni 2 Uber, Lyr in low gain solid state mode and O2 were all very good pairings, showing the powerful, yet tight and textured bass in all its glory.  
From here on out, the Grace m9XX will be what I am using for all further descriptions of its sound, unless explicitly stated otherwise.  It’s been said that these headphones seemed to have been tuned with the m9XX in mind, and it seems hard to argue the point.  They’re a perfect pairing, and the m9XX was sitting on Will from massdrop’s desk in all the pictures of him working on the tuning notes he sent to Fostex.  And while all these further listening notes are based on the m9XX, they would more or less apply to any solid state, linear, sub 1 ohm output impedance solid state amp.  
If you want Grace m9XX specific settings I used, I had crossfeed enabled 95% of the time, on filter F3.  Volume was usually between 50 and 65 (usually in the lower end of that range, with the very occasional rock out high volume session for under 10 minutes.)  Sources were Macbook Pro and iPhone.  Software used was iTunes, Foobar and Tidal.  Mostly iTunes.  Files were a mixture in nearly even parts of FLAC, Apple Lossless and 256 kbps AAC.  A few very occasional 128 kbps mp3 just to see how the headphones handled lower quality sources.
A note about burn-in.  I generally think it’s mostly overblown, and is much more your brain adjusting to the sound as it is anything about the actual headphone changing.  In my mind there are really on a handful of exceptions: tube amps and the large diameter bio-dyna drivers from Fostex.  The construction of these aren’t normal, and they probably experience the greatest improvement with burn in, even if not on your head at the time, of any headphone I’ve ever heard.  Burn these things in for about 50 hours and you will hear a noticeable difference.  The overall signature won’t change, but the bass control, transient distortions, clarity and smoothness are all enhanced with burn out.  At the time of the review these had 180 total hours, 50 of which were actual listening.
In regards to Isolation, it’s sort of somewhere between semi-closed and closed.  Essentially it has a gap around where the cup meets the frame, and some bass ports.  These allow some sound to go in and out.  They probably allow more sound in than they do out.  These ports are similar to bass ports in a full-range speaker, and are part of what gives these things their legendary bass.  Every Fostex TH and Denon DX000 series headphone has had them.  I listen at moderate levels, and my office mate, sitting 6 feet away can’t hear them.  I can hear the phone ring, but I can’t hear myself type when music is playing.  I wouldn’t take these on a plane, but I think they’re fine for office work, unless you listen at hearing damaging levels.  
So… Finally… The Sound:
Starting with the various parts of the frequency response:
Bass (9.5/10 overall) - quantity 9.5/10, impact 9.5/10, texture 9/10, control 8/10
The bass is rocking.  You probably knew that if you have done ANY research on this headphone, but let’s go a bit more in detail.  Headphone bass will always be wonky, because when your brain processes bass in the real world, it gets bass as much from absorption by the body as by the ear hearing it.  Sub bass in the real world is as much felt in your chest as it’s heard by your ears.  As such, it is my firm belief that no headphone bass will ever get it truly right.  It doesn’t matter how it is tuned, you’re throwing away half the equation with headphone bass.  It’s not just a difference in amount of bass either, it’s a different quality and sensation when your chest is absorbing bass.  That being said, there’s a certain naturalness of bass presentation that comes from a headphone with truly powerful bass.  It seems to compensate for some of the lack of body absorption of the bass, and sounds a little bit more true to life.  If you’re just focusing on the bass, these will get you a tiny bit closer to what a natural perception of bass seems like.  It’s a full powerful bass that seems a bit more lively and lifelike than headphone bass that measures neutral.  It won’t rival a truly well-tuned speaker system though, with great subs and midrange speakers, setup correctly in a room, with a correctly tuned crossover.  
These headphones tread a fine balance, and they tread it very well.  In order to give that full bass presentation, they verge on bloat at times.  But they rarely ever drift quite into bloat.  They stay *just* in control the vast majority of time.  There’s a mild midbass hump here, like most dynamic headphones.  The sub bass is slightly rolled off, but less so than any dynamic headphone I’ve heard except the TH900.  The bass seems to hit its peak at 50-80Hz.  midbass slam is very song appropriate.  It doesn’t turn everything into bass mash, but if you have a song with bass, it slams like you want it, when you want it.  
Super Massive Black Hole by Muse has one of the most epic kick drums of all time.  You can actually hear the character of the plate reverb they use on it with a headphone with quality bass.  The beat on the downbeat of beat 1 will be hard, tight and fast.  But at other times it hits and holds on an upbeat, and you can hear the characteristic “shake with a slight low pitched metallic sort of watery sound” of plate reverb.  On a headphone with mediocre bass control, these all sound the same.  The THX00 correctly shows the exact texture that should be present in a good system.  And the slam is epic here, just like it should be, without obscuring the rest of the song.  
Beck’s E-Pro has a tight midbass thump in the intro that gets reproduced powerfully and accurately.  The chorus, however, has an ultra low sub bass thump that many headphones can’t reproduce at all.  In the mastering, this was made so that it would be felt more than heard when the song was played in a dance club with massive subs.  It was designed so that you could FEEL the chorus hit.  It gives the chorus a sort of palpable energy and drive that you really feel without being conscious of when dancing.  The THX00 actually reproduces it.  On a bass light headphone, like an AD700, it isn’t even audible.  On normal headphones you have to really strain to *maybe* hear it.  On my SR225e I notice it because I know it’s there, but probably wouldn’t be able to notice it if I wasn’t already aware.  On the THX00 it’s there and provides a deep power to the chorus that’s addicting.
On Nine Inch Nails’s Closer, the bass has a quick “double tap” pulse to the bass that many basshead headphones (*cough* M50X *cough*) blurs into a single pulse.  The THX00 clearly distinguishes it.  The bass is powerful, but textured and accurate.  Truly impressive for a dynamic headphone.
The bass here is clearly elevated in level above neutral, on some songs this sounds natural, but on some songs, especially those where there’s a lot of upper-mid-bass, it can alter the intended mix of the song.  Dire Straits’s Lady Writer, for example, the bass becomes overbearing in the mix.  It sounds good as far as quality goes, but it’s much more forward in the mix than it should be, the song almost becomes an extended bass solo with some backing vocals underneath.  The flipside is that in a lot of old school R&B and soul, the bass is brought forward in the mix in a *good* way, the mix is changed for the better.  Al Green, Tired of Being Alone, the added bass presence and weight really brings the song alive.  It’s the song as maybe it *should* have been mastered, as opposed to how it *was* mastered.  In mixed results territory, John Coltrane’s Giant Steps sees Coltrane’s sax and the bass get nearly equal billing, in a way that’s interesting, almost like a remix of the song, where the sax and bass play counterpoint off one another, as opposed to the intended mastering where the bass provides drive underneath for Coltrane’s furious blowing.
A great aspect of these headphones though is that, should you wish, they handle EQ very well, and you can actually EQ the mid bass down a touch, bringing it even with the sub bass, such that the bass presentation is virtually flat, almost planar like bass.  Some headphones lose all kinds of control in the bass and become an unwieldy mess when you try to “fix” the sub bass with EQ.  Not here, these handle it well.
These are clearly basshead headphones, but they’re what I think of as “gentlemanly” basshead headphones.  They’re not one trick ponies like the Darth Beyers are.  And the bass blends well.  The bass comes on when called upon, but doesn’t usually insert itself where it isn’t.  Occasionally it elevates a bass line, kick drum, or tom in the mix in an unnatural way, but largely this effect is pleasing.  We should notice that the bass presence frequencies (100Hz-400Hz), in addition to the bass fundamental frequencies (50Hz-200Hz), are also forward.  Kick drums and bass thus sound immediate, present AND thunderous.  I have “oh my god the drums on this track are EPIC!” in my notes roughly 30 times.  If you enjoy drums, you will LOVE these headphones.
Midrange 6/10 - (smoothness 8/10, clarity 7/10, linearity 4/10, lower 8/10, upper 4/10)
(one note here, I am going to call the band from 1.5-4kHz “upper midrange” some will call this a combination of “upper midrange” and “lower treble.”  To be able to talk about this range coherently, I am going to lump them all in here as upper midrange)
One would expect the lower midrange to hopefully also be powerful, as otherwise the headphones would suffer from a lack of linearity in this range, and start sounding wonky.  And that is thankfully true.  The lower midrange on these headphones is pleasingly powerful.  Rhythm guitars sound rich and powerful.  male vocals and lower pitched female vocals (think Fiona Apple, Mavis Staples, Toni Braxton and Adele) are smooth, rich and powerful.  Otis Redding in Tired of Being Alone has his powerful, plaintive pleading vocal reproduced with mastery.  Fiona Apple’s voice in Criminal is rich, sultry and powerful.  Toni Braxton in Unbreak My Heart is goosebump inducing.  Guitarists who like to riff a lot are rewarded with a rich throaty tone.  The riff to Led Zeppelin’s In My Time of Dying is impressively powerful and dynamic.  
The story changes a bit as we start to reach the upper midrange though.  We sort of knew this had to come sometime, as we all knew the THX00 is U shaped, and if some aspect of the frequency response wasn’t at least a little recessed, it would be neutral and not a U-shaped basshead can.  Everything can’t be given equal billing in a basshead can, in that case it isn’t a basshead can.  And this is where it manifests.  The upper midrange is a bit recessed.  Where this is most clearly apparent is that some female voices can be a bit wonky or recessed.  Females who have wider ranges and males who have higher pitched voices can sound especially strange, as their vocals can transition from the powerful and present lower midrange to the upper midrange, all within a single song or even a single part of a melody.  Joni Mitchell, for example, treads right on that line.  It’s like she doesn’t consistently sing into the mic, her vocal tonality is very inconsistent because of this, it can sound disconcertingly weird, like the producer didn’t know what he was doing.  Florence and the Machine’s Dog Days has a similar effect, it sounds as if she can’t keep her mouth pointed at the mic consistently, and then leans in too much sometimes.  Guitar solos that span the range of the fretboard can sound like the guitarist is changing his picking dynamics, leaning into the low end of the solo more than the high end.  Neil Young’s falsetto-ish wail in Helpless from Deja Vu sounds a bit veiled in comparison to a flatter headphone like the HD650.  On Pink Floyd’s Comfortably Numb, the verse vocals are distant, while the chorus vocals (sang at a higher pitch) are crisp, airy and present.  The vocals in the Dixie Chicks’ Cowboy Take Me Away sound very thin and veiled.  The guitars in the Jayhawks’ Blue sound a bit far back and veiled in the mix, like the acoustic guitars are being played behind a blanket.  Marvin Gaye sounds distant in Let’s Get It On’s higher portions, like he’s creepily singing an ode to casual sex from outside your window.  It can get even weirder if the singer has a truly epic vocal range that can go from lower midrange to upper midrange to treble.  Mariah Carey’s vocals could do this thing where they would go from powerful and present when she was doing a deep throaty part, to distant in her normal range, to back to present when she hits those incredibly high falsetto notes that only she can really hit.  Pianos have their twinkle tamed, which at times can be pleasant, but often in jazz puts them further back than they already were.  Gil Evans’ piano in So What from Kind Of Blue gets completely lost in the mix at times.  
This quality is why I don’t think these are great headphones for classical music, by and large, though they certainly aren’t bad.  Daniel Barenboim and the English Chamber Orchestra featuring Itzakh Perlman (chief soloist) on BWV 1042: 1 is a great example.  Perlman’s violin tone, normally rich and intoxicating becomes a bit hollow.  The upper midrange parts of the orchestra become indistinct and blurry.  The St. Louis Symphony Orchestra’s rendition of Rhapsody in Blue sounds overall veiled, as it’s a melody that the upper midrange carries for large stretches of the tune.  
My ultimate issue with the midrange isn’t that it’s a bit recessed (and lord knows it’s much less recessed than in the TH600 and TH900), it’s that I wish the recession was a bit smoother and less abrupt.  If the lower midgrange kind of gradually lowered, and then continued smoothly lowering into the upper midrange, it would be a lot less wonky.  However, the dip in the upper midrange is a bit abrupt.  This is more noticeable because it’s almost immediately followed with another spike in the treble from 6kHz to about 9 kHz.  
It is by no means a bad midrange.  For a closed headphone I’d even the call the midrange a good bit better than average.  It’s smooth, never fatiguing, and rich in the lower register.  And the upper midrange hole isn’t as bad as I just made it sound.  But it is a flaw in the otherwise nearly flawless tuning of this headphone.  If you were going to pull a bit of the frequency response out in a basshead can, that’s exactly where you would pull it out.  I just wish it was done with a bit more deft subtlety.  It was a touch ham-fisted, which makes some sense, since a lot of the tuning was done with the somewhat blunt instrument of pad swapping, rather than an exhaustive, from the ground up, redesign.    It’s a nit, certainly, as I’m essentially complaining that this isn’t a bass-heavy R10, as if it fixed some of these flaws is what it would be.  It’s not that headphone. 
Which Brings us to:
Treble 8/10 - (presence 8/10, clarity 7/10, extension 7/10, airiness 7/10, smoothness 9/10)
While this is certainly a basshead can, it’s not a basshead can in the way the Audeze LCD series are, for example.  Some basshead cans have a very relaxed treble.  Here the treble is very forward and energetic, though it never drifts into sibilance like its big brother , the TH900, often does.  The treble extension from 12-18kHz is good, not great.  It’s not an HD800 in terms of treble extension, but its treble extension isn’t anything to complain about either.  
This present treble makes for a very forward presentation.  This is a “first row” headphone.  If the HD650 sounds like you’re hanging out by the soundboard at a show, the THX00 sounds like you’re about to get kicked out for trying to climb on stage.  
Cymbals sound great, present without being sibilant.  Again, it’s like they tuned this thing specifically for drums in a lot of ways.  Snares are crisp without being obnoxious.  Now, in some poorly mastered songs the treble can be a bit harsh.  The hi-hat in Mariah Carey’s Dreamlover will cut your face off, and is hard to ignore.  Trumpets can really cut, in some cases pleasantly, in some cases weirdly.  Miles Davis in So What, for example has his trumpet sound very present, but lacks body (due to the lack of upper midrange).  The upper midrange wonkiness is thus related, as, again, it can throw the timbre of instruments and vocals off from time to time in this specific range of the frequency band.  
The treble does impart a nice sense of air to vocals though, James Brown’s vocals in Cold Sweat have never sounded cleaner.  All those vocals that were in the lower midrange for the fundamental now see their presence frequencies make them sound present too.  The vocals in Bodhisattva by Steely Dan are very forward, crisp and airy.  
I like the Treble on these a lot.  Nothing stands out about the treble, which is to say they don’t do anything offensive.  A lot of headphones do a lot of offensive things in the treble, so this is a win.  It’s not the best treble I’ve ever heard (HiFiMan HE560), but it is very, very good.  It’s smooth yet forward, which is a considerable feat in a close headphone.  This was stated by Will from Massdrop as being the primary focus of the tuning, and I have to say job well done there.  
Other aspects of the sound as a whole:
Speed: 7/10.  
It’s fast for a closed headphone.  But it can run into issues with very complicated fast passages with congestion.  There are some unresolved damping issues, but not nearly as bad as, for example, an unmodified Denon D5000 or D2000.  Certainly not as slow as the AT M50X. It’s fast enough to handle metal decently (and the bass attack can certainly make certain genres of metal fun)
Smoothness: 9/10 
There’s virtually no grain, the peaks aren’t harsh.  No sibilance, the bass never distorts.  This is a recipe for a smooth headphone, which is extremely impressive for a U shaped headphone, which usually suffers to varying degrees from all those issues.  If the bass is the star of the show everybody is paying to see (Mick Jagger), and the energetic treble and forward presentation is the supporting superstar (Keith Richards and Mick Taylor), then the smoothness is the bed that it lays in that makes it sound so great (Charlie Watts and Bill Wyman).  
Transparency: 7/10 
excellent for a closed headphone.  Isn’t going to best upper mid-fi open headphones like the HD600, any HiFiMan or AKG K7.. series though.  While everything is clear, you don’t get that sense of “hearing through” these.  They aren’t a “close your eyes and swear you’re there” headphone.  They’re clear though.
Soundstage: 7/10 (depth 7/10, width 8/10)
excellent for a closed headphone.  It’s forward, but has depth.  Instead of having the soundstage smushed together all at the front, like the M50 does, it still retains the depth, just shifting everything a bit forward.  There’s great layering here.  On Metallica’s No Leaf Clover from S&M, the depth between Hetfield’s vocals (front row) to the drums (a bit back) to the bass (a bit further back) to the orchestra (much further back) is staggering to hear.  The size of the hall is clearly audible.  Width is natural.  It’s not the widest headphone there is, but it is very coherently wide.  Things sound like the width they should be.  If you’re one of those people that like your soundstage to sound like things are floating in space with no connection, these aren’t for you.  If you want a relatively realistic reflection of the intended space of the hall, just from sitting in the front row, these are very good.  
Openness: 5/10
excellent for a closed headphone, you don’t get a sense of claustrophobia wearing it.  But, it’s not open either.  Unsurprisingly it’s between a typical open headphone and a typical closed headphone
Imaging: 5/10 (left/right 5/10, forward/back 6/10)
Imaging clarity is probably the weakest aspect of the THX00 other than the upper midrange/lower treble dip.  Instrument location, especially L/R imaging accuracy can be a bit blurred.  depth imaging is pretty good, especially for a closed headphone.  The depth imaging would be even better, but the hole means that sometimes instruments/vocals “wonder around” as they or their presence frequencies pass through the upper midrange/lower treble.  That being said, it’s still average here, not bad on the level of, say, a Grado SR60 or the ATHM50.  The width of the soundstage helps, as while the images are not always precise, there’s enough separation that you can still keep instruments from running into each other in the image.  
This is a truly great, refined, basshead headphone.  It doesn’t do anything poorly.  It does several things extremely well (bass and smoothness).  It does have some slight weaknesses (wonky dip in the in upper midrange/lower treble, not the strongest imaging).  It’s good, but not great in most other areas.  While it’s not the final word in resolution, it won’t offend there either.  It’s good looking, I find it comfortable.  And more than anything it’s a fun headphone as long as you aren’t expecting reference level neutrality.  It is an absolute steal at $399.  It’s a $700 headphone, at least.  It would be a bargain at $700, in fact.  It has class leading bass performance (I don’t consider the TH900 or any Audeze offerings as being in its class, costing nearly 3X as much).  My only hope for this headphone was that it would get back some of the joy I experienced with the D7000, and I'd say it succeeded there, and then some, for roughly half the Price of what the D7000 originally cost.  
A Note about EQ:  Eq can largely repair the mid-range issue, if you so desire.  To give you a rough idea of how I EQ these, here is a simplistic adjustment I sometimes use when I use iTunes.  It retains the overall character of the headphones (none of the cuts are more than 3dB), but irons out a bit of the wonkiness, and makes the bass a bit more linear, while still remaining squarely a basshead can.
Head-to-head comparisons I was able to make with somewhat comparable range headphones:
Here I will list a headphone and use a series of “>” signs to indicate how much better or worse the headphone is in this regard.  So, for example, The THX00 vs the AT M50X in soundstage width will be THX00>>>>>M50X, indication that the THX00 soundstage is SUBSTANTIALLY better.
= is, well, equal
> means perceivably better, but not a major difference
>> means much better
>>> is substantially superior
>>>> + is “in a completely different league”  
THX00 Vs Shure SRH840
Linearity: SRH840>>THX00
SubBass (clarity, smoothness, control, linearity, extension): THX00>>>>>SRH840
MidBass (clarity, smoothness, control and linearity): THX00>SRH840
Midrange(clarity, smoothness, control and linearity): SRH840>>THX00
Treble (clarity, smoothness, control, linearity and extension): THX00=SRH840 (THX00 a touch more treble extension, SRH840 a bit more linear)
Soundstage: THX00>>SRH840
L/R Imaging: THX00 = SRH840
Depth/layering imaging: THX00 > SRH840
Comfort: THX00 >> SRH840
Isolation: SRH840 >>> THX00
THX00 Vs Audio Technica M50X
Linearity: THX00 > M50X
SubBass (clarity, smoothness, control, linearity, extension): THX00 >> M50X
MidBass (clarity, smoothness, control and linearity): THX00 >> M50X
Midrange(clarity, smoothness, control and linearity): THX00 >>>> M50X
Treble (clarity, smoothness, control, linearity and extension): THX00 >>>>>> M50X
Soundstage: THX00 >>>>>>> M50X
L/R Imaging: THX00 >>>>>> M50X
Depth/layering imaging: THX00 >>>>>>> M50X
Comfort: THX00 >>> M50X
Isolation: M50X >>> THX00
THX00 vs Fostex TH900
Linearity: THX00 >> TH900
SubBass (clarity, smoothness, control, linearity, extension): TH900 >> THX00
MidBass (clarity, smoothness, control and linearity): TH900 > THX00
Midrange(clarity, smoothness, control and linearity): THX00 >> TH900
Treble (clarity, smoothness, control, linearity and extension): THX00 = TH900 (TH900 extends better, is clearer.  THX00 is smoother and more linear)
Soundstage: TH900 > THX00
L/R Imaging: TH900 > THX00
Depth/layering imaging: THX00 > TH900
Comfort: THX00 = TH900
Isolation: THX00 = TH900
THX00 vs Sennheiser HD650
Linearity: HD650 >> THX00
SubBass (clarity, smoothness, control, linearity, extension): THX00 >>> HD650
MidBass (clarity, smoothness, control and linearity): THX00 >> HD650
Midrange(clarity, smoothness, control and linearity): HD650 >>>> THX00
Treble (clarity, smoothness, control, linearity and extension): HD650 > THX00
Soundstage: HD650 >>> THX00
L/R Imaging: HD650 >>> THX00
Depth/layering imaging: HD650 > THX00
Comfort: THX00= HD650
Isolation: THX00 >>> HD650
THX00 vs HiFiMan HE400i
Linearity: HE400i >>> THX00
SubBass (clarity, smoothness, control, linearity, extension): THX00 > HE400i
MidBass (clarity, smoothness, control and linearity): THX00 >> HE400i
Midrange(clarity, smoothness, control and linearity): HE400i >>>> THX00
Treble (clarity, smoothness, control, linearity and extension): HE400i >> THX00
Soundstage: HE400i >> THX00
L/R Imaging: HE400i >>>>> THX00
Depth/layering imaging: HE400i > THX00
Comfort: HE400i > THX00
Isolation: THX00 >>> HE400i
@[b]fjrabon[/b], really enjoyed your honest review and posts and I'm thinking about jumping on the new drop for the Fostex TH-X00 Purple Hearts.  I was wondering if you think the Purple Hearts will fix some of the midrange and bloated bass problems of the TH-X00 Mahogany?  Lower midrange decreased by about 5 dB and upper midrange decreased by about 2 dB, coupled with more emphasis on the highs seems like improvements to me, albeit small ones.  Throw in extended highs and and no resonance at 3K and 6K Hz and this seems like a no-brainer.  Am i being naive to think that the PH will bring these cans to another level?
Great write up! Thanks for all the info. 
thank you! i love my TH-X00's, came hear to read how they pair with the Grace m9xx. looks like i will be getting that as well... damn you massdrop!


Grand Master Moe "G"….Don't crossface me, bro!
Ping Pong Champ: SF Meet (2016,2017), CanJams (London 2016, RMAF 2016, NYC 2017, SoCal 2017, RMAF 2017)
Pros: Simply enthralling musical presentation to your senses.
Cons: 10 ft long cable with 1/4 inch plug is standard - however you can desolder and solder to replace the cable
Review: Fostex x Massdrop TH-X00
Massdrop has been on a serious roll as of late, releasing audiophile/audio enthusiast products within the last few months that are not only amazing listens but are adequately priced as well.  Massdrop created a collaborative result with $199 AKG – the AKG K7XX, helped to design the $99 CEntrance DACport Slim DAC/Amp combo, helped to design the $499 Grace Design x Massdrop m9XX DAC/Amp, and now, helped to design the Fostex x Massdrop TH-X00 premium reference headphone.  Fostex has been creating headphones since 1949 and the construction of their headphones is top-notch, so to have Massdrop collaborate with a company as well-versed as Fostex is a consummated marriage made in audio heaven.
Unboxing with front, back and right side
My journey to the TH-X00 was an eye-opening experience.  I listened to the Fostex TH-900 at the SchiitShow a few months ago, and liked the presentation out of my QP1R.  I was then told that Massdrop - who was in attendance – had a Fostex and Massdrop collaborative headphone available for listening and was gathering audio enthusiast feedback.  I placed the TH-X00 on my head, listened to my demo track, and was frozen.  I played a few other tracks and all that I could say was “WOW”.  “Wow…wow.  This sounds really good.  The bass is ridiculously good.  Everything sounds so crisp, and the bass!  …How much will this go for?” We are looking at pricing it at around $400 shipped.  “What? Oh man!  That is a crazy price, everyone should get this one!”
Ever since that day, I have been communicating with everyone at Massdrop that I knew, and kept communicating with Will Bright, mastermind with the collaborative effort and fruition of the TH-X00.  It seriously did not matter what the subject was, and Will can attest to this – but I tried to add mention of the TH-X00 into the conversation.  It could be about the DACport Slim.  I will throw a mention of the TH-X00.  It could be about the m9XX.  I will indicate how much I want to listen to the TH-X00 again.  I discussed the design of the cups (which will be covered a little later), and just plain how much I loved how it sounded.  I thank Will for supplying a headphone that is not only one of my favorite headphones that I own, but one of my favorite audio equipment apparatuses that I have every listened to in my life thus far.
Since this is a drop that will be available starting 9am EST on the 27th of November 2015 (on Friday) and will cost $399.99 shipped in the United States.  International shippers can use a forwarding partner for an additional charge of $15.  Here is additional info from Massdrop with regards to international shipping (if you live outside the United States):
Because of strict distribution agreements, Massdrop cannot sell-or-ship this product outside the United States. Understanding that there is demand for this product outside of the US, we have negotiated exclusive pricing with a freight forwarding service to help certain individuals join this drop. If you join, please understand that you are purchasing this product and it will be delivered to a US address. It will then be processed for international shipping by a third-party forwarding company. Tracking will be provided.
At check-out, international orders will be charged $15 for the third party freight forwarding service. You will need to input your shipping address as per a normal drop.
I remember paying around that price when I shipped a Japanese-release-only G-Shock watch to my doorstep, so for Massdrop to charge $15 for a heavier and larger box to an international shipper is truly remarkable in my opinion.
All TH-X00s purchased in the first drop will arrive well before Christmas.
All TH-X00s are individually serialized and the first 250 purchasers in the TH-X00 drop are guaranteed a serial number below 300.
This review will go into detail about the TH-X00, but I will also include solutions, as you have hopefully watched the in-depth video review of Jude’s video in the TH-X00 review thread, here.  What solutions?  As the review thread took off, people were discussing the pads, and the cable was mentioned as well.  I took apart the TH-X00 to look for a solution for included cable if people would want to replace or change it and will be showing how to perform the replacement further in the review.
Let’s go on the journey together to audio bliss…
The TH-X00 paired with the Grace Design x Massdrop m9XX
The TH-X00 paired with the Questyle Audio QP1R

Audio equipment used in the review
CEntrance DACport Slim: $99 shipped in the United States
Grace Design x Massdrop m9XX DAC/Amp: $499 shipped in the United States
Fostex x Massdrop TH-X00: $399 shipped in the United States
Fostex x Massdrop TH-X00 Ebony: $499 shipped in the United States
Fostex x Massdrop TH-X00 Purpleheart: $449 shipped in the Unitied States
HIFIMAN HE1000: $2,999
Master & Dynamic MH30: $349
Master & Dynamic MH40: $399
Sennheiser Momentum 2.0 AEi: $349.95
Mentioned headphones
Audeze LCD-XC: $1,799
Fostex TH-600: $599.99
Fostex TH-900: $1,499.99
MrSpeakers ETHER C: $1,499.99 - $1,649.99 (1/4” 10’ and 4-Pin XLR 10’ DUM Cable)
iPhone 6 (Space Gray, 128GB):  $849.99 or $399.99 with a 2-Year Contract
Questyle Audio QP1R Golden and Space Gray: $899 USD 
Software Applications Used
JRiver Media Center 20: $49.98
Sound Level Analyzer: $4.99
TIDAL HiFi – Lossless: $20 per month or $10 with student discount
Picquic 06102 Teeny Turner 7 Bit Micro Driver (Assorted Colors): Currently $7.91 (Amazon)
A few months ago when I listened to TH-X00, I wrote impressions and added it to my QP1R review.  Here’s the excerpt:
The QP1R drives the upcoming Massdrop TH-X00 to very loud levels.  So much so that at the highest volumes on High gain it can clip, only when low synthetic bass emits. Way too loud to tolerate even for a few seconds. At normal to loud listening volumes there are no issues of clipping.  These are lovely headphones that embody ridiculously thunderous bass.  The massaging effect of the bass may be too much for people, but if you are a lover of bass, these are the ones for you.  This is one headphone to put on your short list regarding subbass as I haven’t heard anything that has as much bass slam aside from the TH-900.  The TH-X00 is for listeners seeking a clear sound, with copious amounts of thunderous bass, a coherent midrange and a non-fatiguing treble.  It’s all good under the mahogany wood!
Fast Forward
When I was able to listen to my own TH-X00, I was happy that the version that I heard a few months ago from what I remember did not sound slightly or significantly different to my ears, and that alone made me a very happy audio enthusiast.  The bass, the midrange, the treble, are all cohesive and sublime.  Thank goodness, I said to myself, as I breathed a sigh of relief.
Build and aesthetics
According to Will, no structural components of the frame are plastic.  Everything is magnesium alloy. Only plastic part is the washers on either side of the earcups where the yolks attach.  This is self-lubricating plastic to avoid the nasty squeaking that people experienced with the Denon D series.  The magnesium alloy looks stately and splendid.   The earcups are made of mahogany with a clear, glossy finish.  This is natural hardwood that's been turned on a lathe, CNC’d out, and coated with a clear, glossy finish.
Mahogany has a lot of natural variation in the color and every set is one-of-a-kind.  Most of the pairs fall into a medium brown color, some may be quite dark, and a couple could be on the lighter brown side. Some pairs may have natural grain variations like burl or knots (very low probability).  My pair is a medium brown color and the glossy finish leads to different variations of the medium brown color hue, depending on the angle you are holding the cups against ambient lighting.  I discussed with Will that maybe another version can have a limited edition color (possibly even less so than the 2000 unit drop limit the TH-X00 currently has on the Massdrop site).  I was thinking maybe a carbon fiber (I really enjoyed the maroon-carbon-type of cup color design the pre-production ETHER C used before going with the all-carbon cup color design for the production models.
Here’s a picture of the pre-production ETHER C model

The magnesium alloy construction of the TH-X00 helps with reducing overall weight, as 12.3 oz (350 g) is a very respectable weight and weighs less to considerably less than most higher-fidelity headphones currently available in the market.
The headband of the TH-X00 has a minimal approach as it is not huge and fluffy like some other models, but has a curve that minimizes the padding needed for the TH-X00 to feel comfortable.

The “TH-X00” logo and “Massdrop” logo underneath are silkscreened on the inside of the headband above the left earcup.  The “Do Not Trash” and “CE” logos are on top of the serial number on the inside of the headband above the right earcup.  Left and right markings are on the rear of the headband – making it very easy to tell which side your TH-X00 is: if you do not see the L and R markings, turn the TH-X00 around – simple as that!
"L" marking with logos on left side of TH-X00


The earpads are made of eggshell protein that allows the headphones to be breathable, as real leather is not breathable.

The size is just right, not too small and not too large.  For those with small heads, the TH-X00 may be a little large fitting.
The TH-X00s are made in China, as are the TH-600s, and most components of the TH-900.
Fit and Comfort
From top to bottom the TH-X00 exudes comfort:
The headband is my favorite fitting band that I have felt out of the headphones that I listened to with regards to comfort, mainly because the curve is engineered as such so it only puts pressure on the top and a portion of the curve of a human’s head.  As mentioned above these are not the smallest headphones, but also not the largest - so finding a position shouldn’t be very difficult at all to achieve.  There are a total of 8 articulating positions available and are best fitted for those that have larger heads.  I have a medium to large-sized noggin, and one adjustment “click” from fully pressed in is all that I need for comfort.
The earcup housing can swivel a good 45 degrees outward from the front on both sides – to the left on the near side of the left earcup, and to the right on the near side of the right earcup.  The headband is elastic enough to significantly allow the earcup housings to be pulled away from each other about 90 degrees.  The magnesium housing is very sturdy and allows for steadfast and confident swiveling.

The earpads, since they are made out of eggshell protein, are breathable and very comfortable.  The earpads are angled from wider from the back and less wide from the front.  The earpads can adjust position by twisting the earpad (not twisting the earpad base) relative to the earcup housing itself– which is an awesome feature to dial in additional individual comfort.  The earpad opening is shaped like an oval and should fit most ears.   As soon as I saw it for the first time, the Master and Dynamic MH40’s stock earpads came to mind, since it uses a similar oval earpad opening design.  Since I have the Master & Dynamic MH40 I was able to measure them both.
TH-X00 earpad on left, MH40 earpad on right

The TH-X00’s earpad opening’s measurements are: Length = 2 3/8 in, Width = 1 3/8, Depth = 7/16 in (Thinnest side/front of head) and 1 in (Thickest side/rear of head).
The MH40’s earpad opening’s measurements are: Length =2 3/8 in, Width = 1 3/8, Depth = 12/16 (3/4) in.
Even though both headphone earpad opening’s measurements are very similar in length, width and depth, the fact that the TH-X00 earpads are angled and allow adjustability with its position seems to create an overall larger opening and more comfortable experience than the MH40’s earpad opening that has zero earpad twisting adjustability.  Also, a simple twist of the earpad’s base, and the earpad will come off from the earcup housing for easy replacement if need be. 
Here's another comparison, this time with the 1MORE MK801 earpad

1MORE MK801 Earpad Dimensions
Inner Diameter: Approx. 33 mm/ 1 5/16 in 
Outer Diameter: Approx. 66 mm/ 2 5/8 in 
Depth: Approx. 13 mm/ 1/2 in
Thickness: Approx. 20 mm/ 25/32 in 
TH-X00 Earpad Dimensions
Inner Diameter: Approx. 35 mm/ 1 3/8 in 
Outer Diameter: Approx. 103 mm/ 4 1/8 in 
Depth: Approx. 11mm/ 7/16 in (Thinnest side/front of head) and 25mm/ 1 in (Thickest side/rear of head).
Thickness (Thinnest side/front of head): Approx. 19 mm/ 3/4 in 
Thickness (Thickest side/rear of head): Approx. 28 mm/ 1 1/8 in
The stock earpads are very important to the sound signature of the TH-X00 - If you suspect the stock earpads may be too small for your ears, you can purchase compatible angled pads such as the Alpha pads or HM5 pads, as suggested by Will.
Mr Speaker Alpha pads (genuine lamb-leather:
Brainwavz HM5 velour memory foam pads:

Since the headband is easy to articulate, earcup housing is easily malleable and the stock earpads are breathable, this all in my opinion leads to a not very tight fitting headphone, and as a result I would say the TH-X00 is more of a semi-open back headphone than a closed back headphone since there is leakage on both ends of the audio experience – you can hear around your surrounds pretty easily when the volume is low, and others can hear the music you are listening to if you have the volume at least a low-medium and higher level.
The TH-X00 stock cable
The cable with included carrying pouch
With my Sennheiser 1/4 and 1/8 in adapter cable ​
The stock cable is gorgeous with the right amount of sheen, thickness, and embodies a tight sheath and braiding around oxygen free copper.  The black, slightly glossy cable is 10 ft long and has a ¼ in plug.  Since the cable is very long compared to most other headphone manufacturers, it is best for home use than traveling around unless you coil the cabling and use twist-ties or Velcro cable fasteners.   The TH-X00 will come with a 1/4 to 1/8 inch adapter for devices that use the 1/8 in/3.5 mm jacks.  For those who may have an issue with the length of the cable, a cable replacement may be in order.  The directions regarding how to replace the cable are in the 
How to replace cable​
 section of the review.  The Y connect is simple and is an appropriate length at around 17 inches lower than the lowest portion of the earcup housings – more than enough room for not just your neck, but your chest, to breathe.  The 1/4 in gold-coated stereo phone plug has a beautiful, meticulously machined look to it.  The plug is solid and has a black strain relief, as do the earcups.​
The stock cable 1/4 inch plug
The weight of the headphone is a welcome reprieve from a lot of the higher fidelity headphones available in the market.  Not to pick on anyone *cough LCD-XC, coughhack!*, but a heavy headphone like that one may be a factor for people to consider a lighter weight headphone, even if the sound of it is very enticing.  I could listen to the TH-X00 for hours just based on the lightweight properties – at only 350 grams without the cable, the headphone is enjoyable and comfortable for long listening sessions or walking around the neighborhood without any significant neck strain either.
Holding onto the TH-X00 at the birthing hospital, listening to music during some of the labor until it's time to put it away and help assist with the arrival of my daughter.
Once you factor in the fact the TH-X00 is relatively lightweight, earpad and earcup customization (Lawton, etc.), nicely curved headband, and the fact the stock earpad are eggshell protein and not real leather with leads to breathability, the TH-X00 is a tremendously comfortable headphone, akin to the comfort level of the lighter weight Sennheiser Momentum 2.0.
How to replace cable
Below are the steps regarding how to replace the cable (please click photos for larger versions):
Twist earpad base counter-clockwise and remove earpad.

Use the Teeny Turner and use the Philips bit to unscrew the four screws on top of the earcup housing.

Place the removed screws in a safe area (on top of the earpad or inside a clear baggie is sufficient)

Remove the four screws inside of the earcup housing with a skinny screwdriver such as the Teeny Turner

The shorter screws are for the outside of the earcup housing, the longer screws are for the inside of the earcup housing

Keep taking out the screws – also the Teeny Turner has a magnet on the end of each bit so it’s easier to remove the inside housing screws, as shown here

Once the earcup is removed you’ll get this – the inside of the earcup

Here’s the cable connections – two leads

Desolder and solder in a replacement cable
How it looks without the earcup and earpad

Cable threading location (2 angles)
The earpad with screws on top, earcup, Teeny Turner and opened TH-X00 earcup housing

Make sure the earcup housing’s slots line up with the TH-X00 housing area rivets (4 angles)
Screw in the inside screws

If the driver and earcup falls off, no worries, you can tighten the screws more and push the driver and earcup into the housing area rivets

Tighten the screws on top of the earcup housing

Replace earpad and tighten

The earcup and magnesium alloy retainer should be flush and taut with no play when all is screwed in

Disclaimer and hearing factors
The TH-X00 sound impressions are mainly for anyone wanting a point of reference regarding how they more or less pair with the iPhone 6, QP1R and m9XX.  Other sources may vary slightly or greatly as the TH-X00 sounds different enough with these three sources to warrant mentioning.  The TH-X00 will have a warmer and pronounced effect in the overall bass region when pairing with the iPhone 6.  The TH-X00 will have a supremely detailed with slight treble and bass with extended detail when paired with the QP1R.  The TH-X00 will have a more balanced and natural approach to its presentation when paired with the m9XX.
We all hear differently, and our experiences with regards to how our interpretation of what we hear vary greatly.  Some factors that come to mind (and not limited), are: 
Your inner ear and skull’s overall composition:
Hearing loss as we age, also known as presbycusis,
Heredity, noise trauma, dietary habits, smoking, hypertension, atherosclerosis, are other factors that affect people’s overall hearing ability.
Sound impressions
I won’t go into crazy detail, but just know these are some serious headphones.  They are fun, but can also be relaxing and if you listen, the detail retrieval is incredible.  Vocals shine through and the bass is elegantly presented.  The midrange of the presentation that flows down to the bass, are the two stars of your own show.  Articulate, slightly weighty but incessantly smooth would be what I would describe the presentation to embody.  The entire sound signature is enthralling and worth a listen.  It may not be a recommended headphone for those who are looking for a more neutral sounding signature, but for those that want a creamy smooth, enthralling sound with loads of supremely high quality bass, you can look no further than the TH-X00.  These are overall my favorite headphone aside from the much more expensive HE1000.  For the price – oh my goodness the price, you might as well purchase one.  I always say, especially for mostly expensive-for-what-you-get audio equipment, to purchase it and if you don’t like it, a friend or loved one will adore your gift to them!  Wait – this is supposed to be sound impressions!  I know…my apologies.  I just really want everyone (or at least all 2000) people who purchase the TH-X00 to give them a listen.  My sound impressions may not match yours absolutely and completely, but there is really no denying the enveloping bass and thoroughly engaging midrange with the smooth-as-silk treble.  For the price - again…for the price, should be enough to run to the Massdrop site with your fingers or thumbs and give them a purchase.  Back to the sound impressions: paradise.  Okay a few more words of encouragement.
The treble has been smoothed/tamed from the TH-900, and listening back to back it shows.  The treble of the TH-X00 is comparatively smooth, but is non-fatiguing and quite easy to listen with an increase of extended comfortable listening time as a result.  I enjoy treble that isn’t extended at times, and the TH-X00 does a great job in this regard, no additional installation pads are necessary to tame treble that wasn’t an inherent concern in the first place.
The midrange can be daydream inducing.  The midrange takes center stage, but lets the rest of the cast perform sufficiently and to the best of their abilities as well.  Male and female vocals are truly alive, instruments pluck, strum and wale with fabulous aplomb.  The midrange is quite an amazing feat, especially when factoring in the technical abilities of the over one tesla of magnetic flux density.
The area where the magnetic flux density would come into play would surely be the TH-X00’s bass.  The bass may be stated to be lessened from the TH-900, but it is still the thunderous bass that I love about the Fostex TH-900 as well.  The TH-X00, aside from the TH-900 has the most favorite sounding quality bass that I have ever heard from a headphone.  Deep, hard hitting, but not obnoxiously so.   Tight and controlled with ever so slight reverberation and decay means you can feel the bass as well.  Add in equalization and possibly an amp with bass boost options and you have an audiophile quality basshead headphone in your hands.  Even without the EQ and bass boost, the bass is magnificent.   The bass may not be as accentuated as the Master & Dynamic MH30, but the bass is controlled and tighter sounding when comparing the two.  Addicting – enough for me to think of it for months after listening to the TH-X00 for the first time months ago.
The soundstage is pretty immense for its 50mm driver and stock large earcups that don’t have the tightest of seals.  We are not talking about a seemingly massive soundstage of the open back and much larger drivers of the HIFIMAN HE1000, but the TH-X00 does a better than average job with regards to conveying a believably natural soundstage.  This will be a thick sounding soundstage for some sources, and wide and invigorating for other sources.  Paired with the QP1R the soundstage of the TH-X00 seems to widen compared to most if not all sources that I’ve listened to.  Pinpointing instrument placements in most genres is an easy task, and the detail is natural sounding with smoothness attached to the spatial facets of the TH-X00.
Overall, the auditory presentation of the TH-X00 is lovely and is easy to toe-tap or relax - kick back your feet if you are so inclined – it’s a jack of all trades and master at most.
The TH-X00 Modification
I have been enjoying the immensely engaging and palpable sound of the TH-X00 for quite a while, but ever since I laid my eyes on the mahogany headphone, I thought the affixed, non-detachable cable was a little too long for my wants and needs at 10 feet.  I immediately wanted a shorter cable, and thought that making the TH-X00 modified with connectors would be a satisfying experience. 
Where do I start?  For starters I have seen modifications but haven't gone through any type of headphone modifications myself - until this process. I knew for sure that I wanted a shorter cable, and a detachable cable connector in the TH-X00 that did not involve making any physical modifications to the wooden earcups or structural housing as well. 
First, I contacted Ted Allen (@teds headfood) from Headphone Lounge to find out about headphone connectors that could possibly be used for the TH-X00 since I knew Ted made some immaculate headphone cables (I own a couple of his Silver Litz cables - simply amazing). He recommended the HIFIMAN SMC connectors for the modifications after discussing connectors such as 2.5 and 3.5mm terminations. 
During this time, I contacted Brian Goto (@Pingupenguins) from BTG Audio, because I know that he makes great sounding cables (I own a couple of his Starlight cables). On his website I saw that he offered the detachable cable modification of the TH-900, using HD 800-type connectors, but it looked like the earcups were physically modified, so that took that possibility out of the equation for me. 
Wanting more input of what terminations I could use, I contacted Brandon Peterek (@PETEREK) from AudMod on Etsy, and after the first couple of exchanges, I knew he was a person I wanted to do business with, not only because he has a lot of experience modifying a multitude of headphones (check his thread ( for various headphones he has modified), but because his communication is fastidious, direct, courteous and eloquent as well.  What I like about people that I communicate with is that they keep me updated about what's going on.  All of my parts took a while to come in (the DHC Nucleotide V3 cable was the main culprit), as well as the holidays played a part in the overall delay, but Mr. Peterek keep me in the loop what was happening.  When I had an issue with the final product, Mr. Peterek was immediate and fixed the issue without any worries.  It's one thing to be courteous when everything goes right before the sale.  However Mr. Peterek was just as courteous and helpful even after the sale and after I received my headphones back from him -- this is what truly makes his customer service first-rate.
With regard to the modification of the TH-X00, Mr. Peterek recommended that I go with the SMC connectors since there won't need to be any modifications done to the wooden earcups. The HD 800 connectors can be installed, but there would be physical modifications that would been to be done (cutting into the wood and frame) - I'll stick with the SMC connectors. 
I wanted to use the stock cable as well so I had him terminate the headphone connectors of the stock cable to SMC so I could use the 10ft stock cable with the modified TH-X00. 
I wanted a shorter than stock cable that was 5 ft in length, copper, and terminated to SMC connectors.  Mr. Peterek suggested DHC copper "Nucleotide" (24 AWG OCC copper) to be used for the additional cable.  I have had first-hand experience of listening to a DJ Khaled H6 connected to a stock cable and then exchanging with a DHC cable - hearing a positive difference between the two.  I did not hesitate to request the DHC Nucleotide.  
At this point I contemplated if I should keep the TH-X00 stock cable from the driver to the SMC connector or replace it with DHC Nucleotide.  After much deliberation with myself, I decide that going with upgraded wire was an option that I should go for, since I wanted to have a seamless integration from the driver to the Nucleotide 5 ft cable that I would use most all of the time.  I also wanted the thinnest 3.5mm plug that I can find, so I chose the quality 3.5mm DHC Elite mini plug instead of the slightly thicker in diameter Eidolic plugs that I am used to.
The materials that are used for the modification are:
HIFIMAN SMC connectors for the TH-X00 and HIFIMAN SMC connectors for the stock cable and DHC Nucleotide cable.
DHC Nucleotide V3 24awg stranded OCC copper:
DHC Elite 3.5mm mini plug:
Simply amazing.  The TH-X00 sounds as blissful as I remember, and the added benefit of the detachable cable modification is almost a necessity for my wants and needs.  With the addition of the 5 ft Nucleotide cable, I can use the TH-X00 much easier as a portable headphone if I so choose, since I will not have to worry about the management of a 10 ft non-detachable cable.  The soldering (Mr. Peterek uses high silver content solder) and the SMC connectors that are connected to the TH-X00 are gloriously beautiful.  The 5 ft cable feels supple and the braiding is something to behold - it often elicits people to touch and look at the cable in awe.  The DHC cable utilizes no Y-connect splitter, so the overall look of the cable is more subtle, and weighs less as well, especially compared to the sleeve-wrapped and thicker stock cable.  The clear over-molding of the SMC connectors at the DHC cable, stock cable (black for left and red for right) and black over-molding at the 3.5mm plug of the DHC cable is tasteful, as PETEREK is blazon over the length of the over-molding.
This is the result of my research and Mr. Peterek's excellent work:
Reterminated Stock Cable with Modified TH-X00 in the Background

Closeups of the DHC Nucleotide V3 Cable

Epic Braiding

DHC Nucleotide V3 Cable with Clear and Black Over-Moldings

Modified TH-X00 Pictures





DHC Nucleotide V3 Cable Connected to Modified TH-X00

Another View

The Setup

Driver to SMC Connector Connected with DHC Nucleotide V3 Cable 

Showing the High Silver Content Solder

I sincerely thank Mr. Peterek for the services provided, and I wholly recommend @PETEREK to anyone wanting modifications performed to their headphones.
If you would like to experience the same modifcations as I, here are the prices for the services (you can email/PM @PETEREK if you have any questions as well):
Detachable cable SMC modification and reterminating stock cable: $110
5 ft DHC Nucleotide V3 Cable: $105
You can request that Mr. Peterek use higher quality wire between the connectors and drivers for an extra cost.

E-MU Ebony earcups (Refers to my TH-X00 Mahogany changed to E-MU earcups, with DHC internal wiring)

I had the chance to purchase the E-MU Ebony Earcups when they were available at this year's Canlanta, in Atlanta, Georgia.  My friend let me choose the cup style I wanted - one pair was more subtle-looking with no lighter brown swirl, and one pair was a lighter brown swirled version.  I chose the lighter brown swirl version because I thought it looked more interesting and unique.
The E-MU Ebony earcups are heavier than the Mahogany, and may be noticed once you change to the E-MU Earcups from the Mahogany.  Some may barely feel a difference, and some may really feel the diffrence.  Initially I did feel a difference since I could clearly feel the difference in weight when both earcups were off, but got used to the weight after wearing it and carrying it around after a couple of days.  The E-MU Ebony embodies a bassy and textured signature, in addition to the warm and intimate sound Mahogany owners have come to love.  Compared to the Mahogany, the E-MU Ebony has noticable bass response, but may seem slightly boomier in sound, but still sounding very good.  The E-MU Ebony is a good choice if you want even more bass compared to your Mahogany earcups, but may experience slightly less clarity and detail across the frequency spectrum as a result.
TH-X00 Ebony

It is no secret, I really adore the TH-X00 Mahogany - ever since I heard the Mahogany at the SchiitShow last year, I knew it was:
One of the best sounding headphones that I've listened to that taylored to my sonic preferences, and:
A headphone that a lot of people were going to enjoy - especially for the price-to-performance ratio.
After changing the Mahogany earcups to the E-MU Ebony earcups, I heard the differences, and liked the increased bass response, but didn't necessarily enjoy the perceived slight loss in ulitmate resolution. 
I received the TH-X00 Ebony headphone to audition, several weeks after listening to my TH-X00 outfitted with the E-MU Ebony earcups.  The TH-X00 Ebony earcups look very dark like the darkest of brown or black, but, when close, you can see not only the lighter brown wood grain and patterns, but you see subtle, classy, yet substantial detail that pictures aren't able to show with superlative success.  Weight between the E-MU Ebony earcups and the TH-X00 Ebony earcups is less obvious than the Mahogany compared to the E-MU Ebony earcups.  The TH-X00 Ebony is slightly heavier than the E-MU Ebony earcups and the TH-X00 Ebony earcups sound and feel denser than the E-MU Ebony earcups.  I was able to hear the difference that the Ebony made over the E-MU Ebony earcups.  Some may think that the difference is from dusk til night, but I hear enough of a difference that it was afternoon to night, to my ears.  The TH-X00 Ebony emits a more smooth sound, with more smooth transitions between all areas of the sound, with bass that was palpable and full of quality texture, but hits just below utter-basshead levels.  Detail is high, transparency and air is further perceived, and you may feel that the TH-X00 has reached another level of performance.  Some might feel the difference isn't that much, and some may feel the difference is immense, as many factors will influence how and what we hear. 
TH-X00 E-MU Ebony and TH-X00 Ebony
By now, I was certain I enjoyed the TH-X00 Ebony more than the E-MU Ebony earcups.  I needed to listen to a Mahogany - and as soon as possible, so I could listen to all three headphones at one listening session to arrive at a better understanding of the three earcups.  I drove my friends @ejong7 and @shiorisekine to Schiit Audio's headquarters (I took them to Mr Speakers and UE the day before - a lot of driving!), and I knew there was a chance I could possibly listen to Schiit Audio's TH-X00 Mahogany because I remember seeing Ms. Martin carrying a pair at this year's CanJam SoCal.  After having a very productive and informative tour from Mr. Stoddard, he had a Mahogany on a headphone stand on his desk.
Me - "Yes! You've got one!  Thank goodness.  May I please listen to it?"
Mr. Stoddard - "Sure!"
Me - "Thanks - I need to listen to yours so I can compare it to this." (I pull out the TH-X00 Ebony)
Mr. Stoddard - "Oh, nice!  Should I get it -- how do you like it?"
I let him know my thoughts, but then I said: "If you want one, make sure to not wait too long to get one, since there will be a 1000 made for the drop".
I listened to and compared the three headphones at the same time:
TH-X00 EM-U Ebony, TH-X00 Mahogany, TH-X00 Ebony (Below represents most what our eyes interpret the look of the headphones)
After listening to all three back to back to back, I will say that all three bring sonic flavors to the table that may be preferred over the other.  I feel that there is no one better headphone since each one can be seen as being the best based on different people that listened to the headphones.  With that said, I feel the TH-X00 Ebony is my overall favorite, since it emits a more smoother and detailed sound, with enough bass to satisfy most all people of the world - except for those that must have TACTION-level bass response and visceral performance.  However, the Mahogany is around 100 grams lighter in weight than the TH-X00 Ebony, and doesn't sound completely different to the Mahogany - I can be happy with the Mahogany since I adore how it sounds.  I can also see wanting to listen to the Ebony as well since it does sound more resolute to my ears.  The Mahogany is also less expensive than the TH-X00 Ebony and E-MU Ebony (the price of the earcups) as well.  If you already own a Mahogany, love the sound and don't have the want to purchase the TH-X00 Ebony, then you may have answered your potential purchase question(s) right there.  If you want a different take on the Mahogany sound, want more resolution, air, delicacy and sweetness, then the Ebony, in my opinion, is the ticket.
The TH-X00 Ebony and how it looks on my head
The bright lighting shows how there are different variations of the wood (looks black and/or very dark in normal lighting conditions)
(Below represents most what our eyes interpret the look of the TH-X00 Ebony)​
The bright lighting shows how there are different variations of the wood (looks black and/or very dark in normal lighting conditions)​
I'll be listening to the Purpleheart soon with the Ebony, and I'll add my impressions and comparisons in the next section of the review.  I will also have the TH-X00 Ebony in tow for this Saturday's Wikia Meet in San Francisco, California, so if you are attending and want to listen, see me, and you can listen to your heart's content!
For now, the Ebony is the pinnacle of my TH-X00 journey, one that I am happy to be a part of.
Both Ebonies are gorgeous
TH-X00 Purpleheart at the Wikia SF Head-Fi Meet
I was able to listen to all four TH-X00's at the Wikia Head-Fi Meet in San Francisco, CA and exhibit all of the headphones with the help of @CEE TEE bringing a Purpleheart to the meet; thanks for that!  The Purpleheart and all TH-X00 variations were exhibited in a corner of a large table in the Questyle room.  Thanks to @bSquared64 for providing the space!
The Questyle room at Wikia's Headquarters in San Francisco, CA
I spent some time to listen back to back with the Purpleheart and the Mahogany, Ebony, and my E-MU Ebony as well, and even though the sonic differences were not very difficult to distinguish, it further made it really tough to choose a favorite headphone of the bunch.  I know - it may not be what you want to hear ("just pick one!") but it is much more than that.  Every headphone variation had a lot of pros and very few, if at all, cons.  
From top left, clockwise: TH-X00 Ebony, TH-X00 Purpleheart, TH-X00 E-MU Ebony (modified), TH-X00 Mahogany
The Purpleheart is the bassiest of the four, and extends into the treble as well; also weighing less than the Ebony.  This is the choice if you want the most slamming bass of the TH-X00 variants and possibly the closest to the TH-900 sound signature of the four, based on my multiple extended auditions of the TH-900.  

The Ebony is the smoothest sounding of the four, but is also the heaviest, with very quality bass and very good reverberating rumble.  This is one that you want to get if you can't foresee minding the extra weight compared to the other TH-X00 variants, and are seeking for the most smooth and possibly resolving TH-X00 in the midrange and midbass areas of the frequency spectrum.

The E-MU Ebony is a more raw form of the Mahogany and Ebony since it has slightly less detail than the Mahogany and Ebony.  The E-MU emits a little less bass than the Purpleheart, and is a good choice if you want a little more texture and true grit than the Mahogany.
Using the Mahogany as a metric and a base, it is the more balanced sound of all four, with very good bass, creamy mids and delectable highs.  
Compared to the Purpleheart, the Mahogany is the more buttoned-down approach to a fun sound.  The Purpleheart is the all-out effort to slam with the best of them.  
When you listen to the Purpleheart and E-MU Ebony, you can hear the difference, as the Purpleheart is the slightly bassier headphone and the E-MU Ebony is the more textured headphone.  
Listening to the Purpleheart and Ebony back to back is where you start to have an appreciation for both of the inherent sound signatures, and that's where it gets to be that much more difficult to choose one that ticks all of your boxes.  Now, I'm not saying to purchase two (or am I), but the reason why I have multiple headphones is that I have different moods.  If I'm in the mood for a treble heavy but beautiful sound, I won't pick up a TH-X00, I'll pick up my ENIGMAcoustics Dharma D1000.  If I'm in the mood for an immensely immaculate presentation of audio, I'll pick up my HIFIMAN HE1000 and become lost in the music.  If I'm in the mood for a smooth, fun take on sound, I'll pick up the TH-X00 Ebony and cherish it.  If I'm in the mood for a bassy, V-signature, very vivacious sound, then I'll pick up the Purpleheart.
Now you've read about the four TH-X00 variants, and one is not better than the other because each headphone has its own qualities that have been brought to the table.  Choose the one that fits your mood:
Purpleheart - most quantity of bass, most fun sound.

Ebony - smoothest sound with quality bass.

E-MU - slightly gritty with slightly rolled-off treble and loads of bass.

Mahogany - tried and true, balanced in all spectrums with engaging bass lift.
Or just catch 'em all.
To hype or not to hype
If you believe in hype, then all aboard the hype train!  If you don’t believe in hype, no worries, the TH-X00 is not hype.  It is quite simply the truth, a headphone that sounds utterly marvelous in its presentation, no hype (positive or negative) is necessary at all.  This is one headphone that a lot of people are going to enjoy.  I usually do not make claims like that, but I believe it – the TH-X00 will be a staple for audio enthusiasts and casual listeners alike to love for many years to come, in my opinion. 
Is the TH-X00 worth it?
Out of all of the headphones that I have listened to, from the free headphones you get when you board planes, all the way up to the $16,000 and more original Orpheus, for $399, there may never be a headphone again that emits a sound that the TH-X00 does, that may be worth multiple times the amount they are being sold for.  For $500 I would not bat an eye. $1,000 even.  Seriously.  For the $399 it is a startling price for the beautiful sound the TH-X00 produces.
The TH-X00 says:​
Experience me…”​
Final thoughts
The TH-X00 is the closest to $399 perfection as you are going to get with regards to a headphone.  The TH-X00 expresses immersive presentation, excellent bass, smooth as velvet midrange, suave treble and a soundstage and detail that is above average because of the clarity of the frequencies presented to you.  What more can you ask for?  Add in the price and you should be sold.  Buy one, listen to it and enjoy for years to come.  If not, give it away to friend or loved one so they will like you and love you even more than they already do.
  1. Fostex x Massdrop
  2. Closed-back design
  3. 50 mm dynamic transducer
  4. Magnesium alloy construction
  5. Mahogany earcups, brilliant gloss finish
  6. Leatherette earpads, matte black
  7. Magnetic flux density: >1 tesla
  8. Impedance: 25 ohms
  9. Sensitivity: 94 dB/mW
  10. Maximum input: 1,800 mW
  11. Frequency response: 5–45,000 Hz
  12. 10 ft (3 m) thick, braided Y cable
  13. 1/4 in (6.3 mm) gold-coated stereo phone plug
  14. Weight, without cable: 12.3 oz (350 g)
  15. Weight, with cable: 17 oz (482 g)
  1. Carrying pouch
  2. 2-year warranty
  3. 1/4" to 1/8" adapter (for use with portable devices)
AT Khan
AT Khan
Man thank you for ALLLLLLLLLL the hard work here. It couldn't be any more detailed now. Respect!!!!
Wow, thanks for the excellent and detailed review. My favorite set of headphones to date are the Beyer DT-990's. I absolutely love a bright, clean high-end/treble and a nice deep but not overwhelming amount of base. I was considering the purplehearts but think that while they would probably have the high end sparkle I enjoy, they'd be too bass heavy. Which of these would you recommend? Thanks again for the excellent review.

Brilliant. Well written and covers so many of the nuances and subtle details that audiophiles will appreciate. Exactly what I was looking for. Just joined the drop for the TR-X00 PH because I was too late for the EB and was curious about the differences.

Anyone have thoughts on whether the Ebony will come back...?


Headphoneus Supremus
Pros: Deep, well controlled low end, rich mids, clean treble without peaks, beautiful cups, price
Cons: Pads could be small for some people, cable is long and not removable, initial run may sell out quickly

Another day, another interesting Massdrop exclusive. It seems to be a trend by now. The first collaboration we saw was with AKG, resulting in the hugely popular K7XX. While based on the discontinued K702 65th Anniversary Edition, the K7XX has some customization in terms of colors, along with a major price drop compared to the original. That's always welcome. Next came the K553Pro - now a standard model in the AKG line and available elsewhere, it was nonetheless exclusive to Massdrop for several months upon release, and again had a lower price than elsewhere. See the trend?
Next, Massdrop collaborated with pro audio veterans Grace Design to come up with the Grace m9XX USB DAC/amp. That little dynamo seems to represent the direction Massdrop wants to go with these things - not just rebadging or exclusive early releases (although those may still have their place) but actually working with a designer to create a unique product. And of course releasing it at a very competitive price. 
The latest project is a joint venture between Massdrop and Fostex. While Fostex may be primarily known for their popular line of planar magnetic headphones (beloved by DIY modders), they also make studio monitors and lots of other gear - including the highly regarded TH-600 and TH-900 headphones. Those models are an evolution of the older Denon D7000 family which Fostex actually created for Denon.
Massdrop collaborated with Fostex resulting in a new member of the family which, in keeping with Massdrop's naming conventions, is dubbed the TH-X00. And it's very obviously a sibling of the existing models. We get the same magnesium frame, and the same long 6N oxygen free copper cable with fancy 1/4" termination. Massdrop's version has some variation which distinguish it from either sibling without departing too far from the successful formula. 

The first, and most obvious difference, is found in the cups. While the TH-600 has black magnesium cups, and the TH-900 uses beautiful Japanese birch maple coated with Urushi lacquer, the TH-X00 cups are mahogany with a clear coat finish. Mahogany is a hardwood with plenty of inherent variation. So each TH-X00 has potential to look somewhat unique - think Audio Technica woodies or the Lawton Audio aftermarket cups, where the theme is always the same but subtle variations do exist. Check out these pics to see how the look has subtle changes based on lighting and angle. These are VERY nice cups, better imho than the original D7000 and up there with some of the better aftermarket options I've seen.





The next difference is the driver itself, which I'm told is very similar but not quite identical to the others. All models use drivers sporting 50mm "Biodyna" diaphragms (a Fostex name for bio-cellulose) and powerful neodymium magnets.The TH-900 claims a 1.5 Tesla magnetic flux density for a sensitivity of 100dB/mW, and the TH-600 claims 1 Tesla resulting in 94dB/mW. That's the main difference between them in terms of specs. I'm told the new TH-X00 is rated at "over one Tesla" which may place it somewhere in between the two siblings. Interestingly, sensitivity is listed on the box as being the same as TH-600, so I really don't know what to make of it. 

Last but not least is the unique pad design which is completely different from that of the TH-600 and TH-900. While those models use a somewhat thin pad which is generally rounded, the TH-X00 has a thicker, asymmetrical design, angled much like the old JMoney pads if not quite as thick. They may actually be closer to the original Denon pads from the D7000 and family. I'm having trouble recalling those since I almost immediately swapped mine out and never used the stock pads again. In any case, Massdrop says the TH-600/900 pads made a huge contribution to their sound signature; and not necessarily in a good way. These new pads are designed to help "tame" the somewhat bright/harsh top end, making for a more smooth, natural presentation. 

First, let's start with the basics. If you've ever worn the similar Denon or Fostex models you'll know exactly how this goes. They are well made yet very light weight which is refreshing in this world of heavy planar designs. The headband, which at first might not seem particularly well padded, ends up being perfectly comfortable due to the low weight. The adjustment mechanism feels solid, with the yolks using the improved hinge system from the Fostex TH models. Apparently the old Denons were known to fail in rather high numbers (mine never had an issue). That, or they just squeaked like crazy. So Fostex changed the design to use a self lubricating washer - problem solved. 
If you're new to the "family", and looking for a great sealed headphone... be aware that these things don't isolate much. The somewhat loose fit combined with the cup design makes for little sound reduction in either direction. So, you'll hear people talking in the room next to you, and they might hear your music if played loudly. They still don't leak as much sound as a true open headphone. We're talking isolation/leakage just barely surpassing "semi-open" models like the beyerdynamic T1. Keep the volume reasonable and you should have much trouble - just don't expect complete silence and isolation. 
Impedance is 25 ohms meaning these things can be driven comfortably from low power sources. A quality smartphone will sound very respectable (you'll need an adapter for the 1/4" plug though), though it obviously won't unleash the full potential of this headphone. They don't need a powerhouse amp in terms of juice but definitely scale well with more a resolving chain. A higher gain desktop amp may actually be problematic when it comes to range of volume adjustment. I ran into that with a few devices including my Questyle CMA800R which sounded killer but was tricky to dial in "just right". I ended up having excellent results with many of the better integrated DAC/amp units I have on hand. The Questyle CMA800i, B.M.C. UltraDAC, Aurender FLOW, and Anedio D2 all drove the TH-X00 exceedingly well. Those results are clearly linked to all the units having very low output impedance, very low noise, and reasonable gain. And, of course, the Massdrop exclusive Grace Design m9XX was a dynamite pairing. It has all the juice one might need, and that top-mounted volume control is a joy to use. 



Unfortunately, my ears prove somewhat incompatible with these new pads. The initial fit seems cramped, like I have to maneuver my ears in a certain way and almost "tuck" them into place. If not, the rear of the pads sits on the helix of my ear, which is not the most comfortable thing for long term listening. The pads are made of a protein leather which seems very similar to those on the TH-600/900 (which Fostex calls "eggshell membrane"). I didn't have trouble listening to the TH-900 for hours, so I'm thinking it's the shape I have an issue with rather than the material. Massdrop tells me they have not heard any other complaints from other testers so this is likely an issue unique to my big, weird head. If you achieved a good fit with the Denon D2000 and friends, you'll likely be fine with these too.
Having fit issues makes it somewhat tough to judge these as I normally would. I just can't put in the hours of listening required to nail down a final conclusion. So I'll have to temper my excitement a bit. Thus far I REALLY like what I hear though. TH-X00 seems to take everything I loved about my old D7000 as well as the TH-900, fixes a bunch of the problems, and sells it for a much lower price (I'll get to that shortly). What's not to like?
The first thing that strikes me about these things is the bass impact. This was something I loved about my D7000, and loved even more about the TH-900. Yep, it's still here, not at all diminished. It hits hard and goes extremely low, with killer sub-bass extension that few other headphones can match. I like to think of the LCD-2 as having great bass but when I compare the TH-X00 to my LCD-2 (pre-Fazor) I'm surprised to find the Audeze somewhat soft in comparison. A little indistinct, where the Massdrop/Fostex collaboration has more definition, or more meat for lack of a better word. Bassheads will love this sound, though I suspect most "regular" folks will too. This is not the type of droning, overbearing thump that tends to annoy... this is excellent, high quality slam which does not step on the mids in the least. If you listen to classic rock or jazz or grunge or pop, these will sound energetic and fun, not necessarily neutral but not too wacky either. If you play something with more propensity to show off bass - Pendulum, Blackmill, Pinch & Shackleton, that sort of thing - the TH-X00 will rumble like few other headphones - but even then it won't become a one trick pony like a Darth Beyer. The bass gets low and loud but remains controlled and doesn't come at the expense of any other frequency.  
The next aspect I enjoy is how open sounding these are. Completely different from the stereotypical "boxed in" feel of many closed headphones, these things could easily be mistaken for open or at least semi-open cans. Soundstage is large and effortless. It won't compete with my HE-1000 and HD800 but for a "closed" headphone it is among the best I've heard. Imaging is accurate but falls a bit short of the best. Still, nothing to complain about here, these things are impressive. You'll definitely want to drive them from an amp with low output impedance. These are among the lowest impedance full size headphones you'll find, so tube amps are generally not such a good match (though I'm sure exceptions can be found). 

Highs are one area where I feel the TH-X00 is actually better than the TH-900. I don't hear the same sharpness around 6 or 7 kHz, yet I also don't feel they have diminished capacity for revealing microdetail. While my Stax or HD800 won't feel threatened by the detail retrieval here, the TH-X00 still digs deep enough to satisfy in most situations. I'd call it a good balance, where cymbals ring out with characteristic splash, and brass instruments have the appropriate amount of "blat". I can see how die-hard TH-900 fans might find this model lacking in excitement... but I could also make a case for them being thrilled that the treble is less splashy without losing much energy overall. It's hard to say as everyone describes the TH-900 a little different. Regardless, I think these will prove less polarizing overall due to their superior technical performance. 
Midrange initially seemed more forward compared to my recollection of the TH-900. After more listening I'm still not sure if that's really the case, or if it's merely a byproduct of the superior treble-to-mid ratio. But when I listen for that characteristic midrange dip from the TH-900, which seemed centered around the critical 500Hz range (give or take), I'm not really hearing it here. Maybe just a touch, but very, very minor. I heard a D7000 not long ago that I really enjoyed, and the owner told me it came from one of the last batches made prior to the line being discontinued. It sounded remarkably better than any D7000 I had heard before. I've heard other reliable sources (Tyll included) mention the same thing. Apparently Fostex got their act together on the later models, resulting in a more linear presentation than before. Well, I'd say the TH-X00 has a lot in common with those. Mids are still lush and creamy, but this time around singers aren't buried quite so deep in the mix. This headphone makes a great counterpoint to the HD800 for those times when I just want to let the music flow. 
Did I mention these things will go for $399? Yep, $399 for what is arguably a better headphone than the $1,299 TH-900. Very likely better, based on my admittedly limited experience, than the TH-600 which after recent price drops still goes for $599. The Denon D7000 was $999 before being retired and this TH-X00 is easily on par with that as well. So we're talking killer value here, without a doubt. 
My only reservation is the earpad fit. They just don't work all that well - FOR MY EARS. Not saying that will apply to anyone else but me. Which makes me curious to read the other reviews once this posts, as I can't reliably say this same sound will be heard by others. I had grand plans to pick up a bunch of different pads and see how they work, but unfortunately I ran out of time. So far all I have is the velour pads from my K7XX which don't fit permanently but do stay in place when worn, as a sort of "proof of concept". They sound different, more neutral in the lows and a tad brighter, but still quite enjoyable. This leads me to believe I'm in for quite an adventure rolling pads. I can't even recall which ones actually fit without too much trouble. Alpha Pads? Beyerdynamic velours and gels? HM5 pads? Surely at least SOME of those will fit well. I may have to try the Lawton angle pads too. I wish I still had my old JMoney pads as those were just about perfect on my D7000. 
In any case, Massdrop and Fostex have achieved something pretty special with this release. I almost feel bad because new TH-600 sales will probably drop like a rock after these come out. Maybe Fostex has plans to retire the 600/900 soon anyway. If you're in the market for a "fun" or "musical" headphone, don't want to spend a fortune, don't want something so ridiculously colored that it only works with a few genres, and aren't willing to put up with major flaws just to get your bass fix, the TH-X00 is absolutely recommended. 
The product page can be found HERE and ordering goes live on Friday the 27th. This drop will be limited to 2000 units.
Ew, yeah.  They've gone up a lot since I got mine - I want to say I paid around $60 a few years ago.
At the end of this great review you mention you are excited about pad rolling with these but ran out of time. Since it's been nearly a week since you posted, can you please update us on any results you have?
How do theses compare to the SRH 1540 ?