Fostex TH900 Review


Fostex TH900 Headphones ReviewFostex TH900 Review: Standing tall as Fostex’s flagship, the TH900’s are an outstanding pair of headphones that are at the top of their game. Exhibiting a dreamy U-shaped frequency response and a stunning Urushi finish these headphones are a work of art and come highly recommended.

Review Preface:

Japanese born Fostex has been a manufacturer of audio equipment since 1973, and is a subsidiary of the ‘Foster Electric Co.’ conglomerate. Initially developing custom loud speaker components with the intention of selling direct to Japanese ‘home brew’ enthusiast, the brand came from humble beginnings. However, the development of multitrack recording took off and subsequently skyrocketed the brand into the global sphere, slowly becoming a notable figure within the professional audio sector. Continuing to build upon the growing affordability, and thus popularity, of portable multitrack recording equipment, Fostex became a household name that really specialised in two areas; transducer design and hard-copy recording technologies. In recent years Fostex has expanded into the true ‘consumer audio’ and ‘HiFi’ markets, and has certainly made an impact. As a result, today we shall review their flagship reference headphones. Named the TH900’s, these headphones were released in late 2012 and they truly represent a beauty and the beast tale.

Unboxing, Build Quality, and Features:

As expected, the TH900 package is meaty and looks rather smart, however it is concealing two dark-grey heavyweight textured boxes; one packed with the headphones and a carry case, the other with an accompanying stand. At this point I do have to say that I, personally, feel that the headphone stand should never have been included. I say this for a number of reasons, but first this disappointing item is poorly packaged thanks to the use of just a single foam baffle to stop it from rattling around, and potentially causing damage, during shipping. In terms of construction and aesthetics, the headphone stand is rather budget as it is a hollow core cast aluminium design with a simple black matt powder coated finish. I fully understand that the reason for why this headphone stand has been made to look so inconspicuous, as to not detract from the beauty of the TH900’s design, but its economy shape and construction is fundamentally flawed. This moderately tall headphone stand has a very narrow baseplate and absolutely no rubber feet to increase the grip with the target surface. The problem with this is that the stand has a habit of skating across a work surface when in use, but, on top of this, the TH900’s large circumaural design and high 400g weight has a high centre of gravity on the stand, which makes the whole outfit liable to toppling from touching the structure, or removing the headphones. Understandably this is not a fate that should ever bestow a pair of finely crafted £1000+ headphones and, likewise, the fact that the headphone stand is missing stoppers at the end of the rail is a fatal mistake, for obvious reasons. Just to conclude, I also feel that the general build quality could be better as the welding feels gritty, and it’s such a poor show. Simply put, this headphone stand would have been a nice inclusion with the lower price TH600, but, placed into what’s meant to be a ‘king of kings’ package, there is absolutely no need for it – you’re best to take a look at the Sieveking Omega stands.

It fills me with sadness to make the above comments, although from here on in the analysis takes a overwhelmingly positive turn as the TH900’s are godly.

Just before we rush into the headphones themselves, it’s nice to see that the second box, or presentation case, is very well packaged with custom cut medium-high density foam which encapsulates the headphones. Clearly there is no way that they are going to get damaged during shipping, unlike the headphone stand. Funnily enough Fostex have included a very simply nice black softness with the TH900’s. This humble case can help to stop dust build up when not in use, or on a stand, but it really would have been nice to have a hard-case included – like many other brands offer at this price-point. Either way a soft-case is included and it fits the headphones perfectly. The case is made out of the same special material as the soft ear pads, and headband, but this is a complex material and, to save yourself from having to read repeating lines, I’ll come back to this material in a short while.

Starting with the cable, it has to be said that it feels really nice, ultra resilient and, interestingly, Fostex note that the cable has been specially designed to help with low frequency reproduction. Our tests have shown that the cable flexes well, although it is quite heavy, and doesn’t tangle an awful lot. This does, however, change when you get past the Y-Splitter because the cable has a habit of wanting to tangle itself. Clearly this is a common problem with independently wired driver housings, which do not have a single connection from a master driver to a satellite housing. However, the benefits with the way in which the TH900’s are wired comes down to comfort and psychoacoustics. Using a master to a satellite connection can, not only be annoying, but also become uncomfortable for the user when a weighty cable pulls on the master housing. In terms of psychoacoustics, the cable length discrepancy between one driver and another can introduce a tiny latency between both drivers which ultimately results in a phase misalignment. Even 1ms of latency can have an impact on the users perception of a soundstage, so Fostex precision cut the cable lengths in order to avoid this phenomenon. The result is a crisp and texturally rich soundstage with excellent stereo timing (aka. how an instrument reacts within a three dimensional space). Coming back to the cable construction now, Fostex have opted to use a very thick and ultra high quality 7N (3.66mm) Oxygen Free Copper (OFC) core conductor with 99.99999% purity. Unfortunately Fostex have not disclosed the detailed cable construction or shielding properties, but the exterior clearly uses a durable woven nylon jacket that should last a very long time – there’s no way this puppy is going to get caught in a zip, or be damaged by it. Considering the above you would imagine that the cable would be heavy and have limited flexibility, but you would be partially wrong, Fostex have tried to cut the weight as much as possible whilst trying to keep the same quality, although in terms of termination, the TH900’s have a sole (standard) gold plated ¼” jack plug, and sadly Fostex did not include a ¼” to 3.5mm converter. With that said the termination feels ridiculously solid, as the entire construction is metal. Now Fostex have even payed special attention to the plug jacket, just like they have with everything but the stand, because it has been machined from a single billet of Durilium to keep it bullet proof, unlike other brands who just use an injection moulded plastic jacket method. Something that does appear to be missing from the construction is a moulded strain relief mechanism at both ends of the cable, but my suspicion is that Fostex have opted to use a clamping mechanism within the housings. Coming up the Y-Splitter there isn’t really anything notable, apart from the fact that it is quite low (40cm from the driver housings), which makes it a bit awkward. Finally the cable length comes in at 3m, meaning that the listener can comfortably sit some way from their HiFi and still be comfortable. For desktop equipment users the length of cable may be frustrating, although I, personally, have not had too many issues with the length, more so the length from the Y-Splitter to the cups.

Moving your eyes up from the cable and onto the driver housings you cannot help but be in awe of their classic appearance and sophisticated red hue. The cups hold an audience of their own, and are paired with, what appears to be, a simple headband construction. A first glance of the TH900’s could fool you into thinking that they have been crafted from some metal alloy, what with a galvanised zinc looking lower layer and brilliant continuous red resin finish, but Fostex have gone all out on a limb by making each pair of their TH900 flagship headphones unique through the a 100 year old Japanese art form known as Urushi lacquering. With a finish known as Bordeaux, it is this meticulous father-to-son process that creates a finish that differs depending on the ambient light conditions. In daylight conditions the red is vibrant and multifaceted, textually rich, and lively, but as day turns to night the red finish comes across as deep and moody, it looses some of the texture contrast and appears regal in tone. Fostex begin this process with machining a block of Japanese Cherry Birch (AKA. Petula Grossa). This material has been for its high density which contributes to a rigid structural integrity, but, as is expected, has excellent acoustical properties including excellent isolation and a medium-high reflective quality, even when paired with the softly packed internal cotton baffling, that helps to create a superior soundstage and perception of space without softening the bass frequencies, or muddying the midrange. Using the Cherry birch as a lower material, a black lacquer base is applied before a layer of small jagged cut sulphur smoked silver foils is hand stuck and then dusted to remove any excess. To achieve the Bordeux tone the cups are hand lacquered many times with (Dracaena Cinnabari – AKA. Dragon Blood) tree resin that naturally oxidises create to a deep multifaceted red colour. Once completed the ‘Fostex’ logo is applied in the form of a single continuos sheet of platinum foil.

In terms of the general structural integrity the Fostex TH900’s are solid. They have a nice feeling to them, probably due to the fact that there is absolutely no plastic used within the design, and generally the TH900’s feel lighter in the hand than their reported weight of 400g. When worn the headband doesn’t feel too heavy, the weight exponentially appears to be coming from the earcups. It’s a strange sort of sensation that feels a touch off centre, but this is most likely due to their huge 10cm (4”) diameter that completely covers the ears rather than sitting against them. Thankfully the mechanism that joins the cups to the headband has a bidirectional pivoting point that has a limited range of movement to allow the cups to sit flush against the shape of the head. In use there is a glutinous comfort factor that seems to work well and, for larger heads, there is an eight stage stepped headband adjuster that has a good amount of grip, although it would be even better if the steps gripped better to their stage. Arriving at the headband, it feels as if it has a decent amount of flex and this helps go towards the comfort factor as it does not harshly clamp the head. In terms of padding the TH900’s are right on the money as the ears standoff at a good distance from the driver grilles, but the foam used does not have any memory properties and just feels like a standard low-medium density product. Regardless, both on the headband and ear pads Fostex have opted to ditch leather and instead use an interesting semi-permeable material made from eggshell membrane protein. This revolutionary material is ultra comfortable and compliments the soft butter skin of the ear well without any abrasion, but this material is said to be durable and has reduced the potential weight by 60% without getting too hot at all over an extended period of listening. When you combined this with the flex of the headband wearing the TH900’s sort of feels like sleeping on your favourite pillow, it’s really very comfortable, but you wouldn’t want to take it around with you – the TH900’s are strictly indoor headphones, they just have too much instability that if you were to move your head around they have the potential to fall off. If you’re wondering if the TH900 ear pads can be user replaced the answer is yes, just a simple anticlockwise twist unlocks them from the plastic mechanism. The only problem is that the headband is, unfortunately, not user replaceable. Please note that third party modifications exist for the Fostex TH900 and some users have reported an increase in sound quality by replacing the ear pads with angled leather pads. Other modifications for redesigning the shell and replacing the cable do, also, exist, it just depends on how far you’re prepared to go as prices vary from an insane $200 – $1500 (ref. Lawton Audio).

So far we have seen that the Fostex TH900’s have a deeply impressive wrap sheep, but the most impressive technology is inside the driver housings. To produce the TH900 headphones Fostex developed a 50mm driver using custom neodymium 1.5 Tesla driver technology with a super impressive 15,000 gauss magnetic field; put it this way, that’s about the same pull as 300 fridge magnets. Fostex paired this neodymium heart with an ultra-low mass bio-cellulose diaphragm to give the TH900 true flexibility with dynamic contrast (down to a macro-level) and imaging, but, as a result, the frequency response ranges from an incredible 5Hz – 45kHz. Whilst you may wonder what’s the point of a driver truly extending past the human range of hearing, the fact is that any extra room around the 20Hz – 20kHz frequency band can help lower distortion at the extremes and create a refined listening experience – it certainly makes sense when you listen to the TH900’s!

Passive Noise Rejection:

It has to be said that the passive noise rejection capabilities of the TH900’s isn’t exactly the best considering their price point and closed back format. During playback external ambient noise is sufficiently isolated and a comfortable TV volume, at distance of 3m, was almost partially undetectable. However, when worn, I would consider the leakage to be about average when consumed at a sensible listening level. Listening in the same room as someone may prove to be irritating as vocal sounds appear pronounced amongst anything else.

Test Equipment:

Various lossy and lossless files (44.1k to 384k – 16bit – 24bit – No MP3’s), i7 MacBook Air, Sonic Studio Amarra, Pro Tools 9, Chord Electronics Hugo, Lynx Hilo D2A/A2D converter system, ARCAM irDAC, CAD USB, and Fostex TH600.

Please note that during testing with the Chord Electronics Hugo we found out that, despite their rated 25Ω impedance, they were particularly thirsty and managed to drink their way through an nine hour battery in less than five hours. This is not a problem, more a side-thought for future reference, and this knowledge could prove useful if you intend to use the TH900’s at home with an audiophile DAP (we’re looking at you Astell & Kern).

Sound Quality:

At the time of writing the TH900’s are exactly what you should expect for their premium price tag; nothing more, nothing less. Whilst the sonic characteristics are certainly spectacular to anyones ears, the TH900’s have a unique sound signature that is, perhaps, different in comparison to the competition, or what you would typically consider from a flagship product. Again, this is not to say that these headphones are slacking, but that they feel like they could have been pushed ever so slightly to produce a product that is at the very top of its game in the premium market. In fact this is probably where Fostex TH900 owners look to Lawton Audio to provide them with modifications that elevate their performance to untouchable godly levels. With this said a general overview would describe these headphones as harbouring a warmish yesteryear tone that works well with a wide variety of genres and sources, although a good amplifier has a habit of further increasing the depth and analogous sparkle.

As we’ve now established, the TH900’s aren’t exactly what you would describe as neutral, this is a pair of headphones with a forward low end presence that, frankly, epitomises the word ‘power’ and delivers a full, larger than life, rounded, slightly loose, low end frequency response that bops along well with a strong bass line and percussive sub-bass grooves. You may think that I’m mad for saying this, but to get what the TH900’s are about without listening to them you have to imagine a strong orange colour, or a rising sunset. With this imagine it’s important to understand that if you intend to pair the TH900’s with a warm source, such as a vacuum tube amp, that you may find this pair of headphones fatiguing, because it can get too much. The only reassurance here comes from the fact that the TH900’s are very continuos across a range of volumes and still regain their general composure at lower levels and sport a wider than average appearance on the soundstage. Forgetting this for a moment, if we come back to the aforementioned frequency response of 5Hz – 45kHz, it’s certainly evident that the TH900’s extend low indeed, and this is where the previously stated ‘power’ descriptive comes from. With well produced recordings the bass frequencies capture all the smooth creaminess from the baseline and seem to act as a crook for the low-midrange to be built upon as the frequency boundaries seamlessly merge into each other; a quality that works particularly well with Rock genres. However, before moving on to the midrange, the bass seems to be presented with a slow to medium degree of attack that is paired with a moderately slower decay which, again, builds upon the fullness and orange imagery here, but, because of these qualities, if you encounter a track with poor ducking compression (AKA. Side Chain Compression) between the kick drum and bass line the two can have a habit of merging into each other and creating a pumping sort of feeling. With all things considered, the bass is beautifully sweet, velvety, and is probably one of the most beautiful aspects of these headphones considering how well they follow the vibe, ebb, and flow, of a decent groove. Having previously mentioned that the TH900’s are an excellent all around performer, but they work particularly well with Rock genres and would best suit ‘clarity conscious’ [audiophile] bass hunters. I do have to say that with the TH900’s you get the feeling that the bass actually has its own place amongst the soundstage’s X and Y axis. The bass doesn’t appear massively central and stuck on your ears because there is an element of air that carries it across and forms its own mildly central space within the sound sphere. Usually you would think that this is a problem, but when you have this resolution it is far from that, its positioning actually feels consistent with a natural live performance.

Working our way up to the low mids now, this is a region that also seems to exhibit the same relaxed, comfortable, analogous, fluid sort of vibe, as a natural extension from the super voluptuous sub-bass to mid-bass region. With the TH900’s you, thankfully, experience this warm endearing vibe, but Fostex have managed to not make this area over exposed or sluggish in composition. Even though this is such a small point to make, I do feel that if the 200Hz – 260Hz region was tapered by 1db then the thick creaminess could prevent certain mixes from becoming clouded. With that said the mid-midrange is slightly lower in the mix than the bass and low-mids, but it is, otherwise, heavenly and very nimble. The nimbleness in this region actually comes from the perceived flatter frequency response and open back feeling, which allows complex instrumentation to dance around each other – particularly with classical recordings using complex microphone positioning techniques. On paper you could mistake these words for suggesting that this is a thin or lifeless region, but this is so wrong. The midrange is rich in its own way and has a natural feeling that is not recessed. This leads to beautiful transmission of male and female vocals, which come across as so creepily lifelike and entirely accurate. This is why I love these headphones, because the midrange is present, super well constructed, and complex. But, again, as you work your way up to the high-midrange you are greeted with a sort of pillowy transparent texture which compliments the synergy of the bass and midrange areas, although the composition is reigned in ever so slightly.

In terms of the low, mid, and mid-high treble frequencies, they appear to extend well and are apparently free of any hollowness or imbalance, however the super-high frequencies feel, in comparison, slightly pushed back in the mix in order to prevent any sibilance from ever becoming a problem. During playback the treble frequencies appear to be symbiotic with the bass frequencies and, through their beautiful harmony, you are presented with a luscious, powerfully deep presentation, free of any hollowness, that is untaxing on the ears when consumed with a well produced album (ie. Steven Wilson – ‘The Raven That Refused To Sing’, Hans Zimmer – ‘Inception’, and Damien Rice – ‘My Favourite Faded Fantasy’). In continuation, even at extended levels, the TH900’s seem to be immune from distortion that would, otherwise, crush the transparency of this frequency range and I do have have to credit the TH900’s as being one of the best pairs of headphones that I’ve ever listened to for the air they manage to hold around the instrumentation; their treble soundstage is truly vast and rich in contrast. If you encounter a gritty vocal line the TH900’s are so revealing that you can hear all the complex elements as a coherent entity, it’s actually quite incredible that micro details are able to be picked up individually when critically listening to a specific element yet, when you relax everything melts back to become a deeply personal experience.

As expressed throughout this ‘Sound Quality’ section, the TH900’s have a moderate U shaped frequency response and encapsulate the traditional Hi-Fi sound perfectly. In terms of the soundstage the TH900’s presentation is vast, more like a stadium feel, with a beautiful sense of air and dreaminess that never appears too over the top. Everything just feels so agreeable and organic with the TH900’s and there is no doubt that they are one of the best sounding headphones that you will come across for the current retail price.


With an outstanding build quality, an incredible traditional Japanese Urushi finish, and a deeply personal (U shaped) sonic approach, there’s absolutely no denying that the TH900’s are a truly beautiful pair of headphones. We would love to award the TH900’s with a full five star rating, however sometimes the bass presence can become a bit too much and the inclusion of the headphone stand was a deadly mistake. With everything considered, we would like to award the Fostex TH900 circumaural headphones with a four and-a-half star rating, and our Editors Choice award.

Edd Harris

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