Fostex TH900 mk2

The Second Edition of the Well-Known High-End Headphones

Fostex enters the fray of high-end headphones with the Second Edition mk2 of the TH900. The dynamic flagship model from Fostex impresses with meticulous design features and a technically and visually sophisticated choice of components.


If you’re after something a little extra, it’s all on offer here. Specialist woods, exclusive paint finishes, magnetic flux density, special tuning; it’s all available. Admittedly, these premium extras come with a price tag to match.

Not long ago, I was lucky enough to come into the possession of some extraordinary headphones. Before the courier even rang the bell, I already knew what was coming. The Japanese manufacturer produces models in small quantities by hand using specially selected materials. Fostex is thus joining the reputable ranks of other Japanese manufacturers, such as Pioneer, Sony and Audio-Technica, who all opt for intricate combinations of components for their respective prestige products, combining traditional and state-of-the-art technologies. It’s truly a case of class over mass.


The TH900 mk2 is delivered in an elegant yet robust black cardboard box which is in turn wrapped in an outer layer of packaging. As a special treat, inside there’s a matt black lacquered wooden headphone stand. This, combined with the headphones themselves, makes a first-rate impression in the studio or on a sideboard or shelf in the home. A glossy brochure, multilingual operating manual, certificate of authenticity and a soft, black carry bag with drawstring fastening round of the box contents.

Haptics, Optics and Wearing Comfort


The most eye-catching feature of the TH900 mk2 is the Bordeaux-red lacquered ear shells made of Japanese ornamental cherry birch. The rigid structure of this precious wood, which is also regularly used in high-end furniture production, is said to have special acoustic properties in addition to its robust high density.

On the website, there’s an almost meditative video about the Urushi varnishing process of this wood, with the video demonstrating individual steps clearly. The final result makes for a stunning texture, which never fails to impress. The paintwork also serves to extend the longevity of these headphones. What’s more, perhaps befitting of an asking price of around 1,500 euros, the Fostex logos on the ear shells are made of luxurious platinum.

These headphones weigh 390 grams without the cable, therefore falling in the upper range when it comes to dynamic headphone models. The weight is very well distributed throughout the headband, which is completely covered in artificial leather and boasts padding at the crown. However, the wonderfully padded earpieces, also covered in artificial leather, are fixed to the side of the headband with a little less contact pressure, resulting in the TK900 mk2 pulling notably downwards during longer listening sessions. Due to this peculiarity, they tend to become a pseudo-closed pair of headphones, which does not provide superior bi-directional sound insulation from your surroundings. However, as the headphones are not specially designed for use on the go, but rather studio recording applications, it’s not really a technical problem worth focusing on. The wearing comfort of these headphones is particularly appealing. Both the protein leather; made from eggshell membranes, plus the luxurious padding caress the ear when the headphones are worn.

The earpieces are placed very securely vertically via steel bracket attachments. In addition, they can be easily tilted and turned. If you’re sitting relatively still when wearing them, then a perfect fit is all but guaranteed. If, however, you’re moving while listening, the headphones, unfortunately, move a little and you’ll be forced to readjust them from time to time. Although I’m not a big fan of a tight fit, the TH900 mk2 would have benefited from a slightly higher contact pressure, especially if you think of users with slightly smaller heads.

The 3-metre long, double-sided cable weighs in at 120 grams and is made of oxygen-free 7N copper of the highest quality class (99.99%) and has textile sheathing that is becoming increasingly utilised. In the mk2 version, the cable is now also removable (an additional symmetrical cable can be purchased separately).

Fish out the plugs and you will see Fostex’s own 2-pin connector, which indicates the orientation of the connection via the R/L embossing. Personally, I prefer fused and locked plug connections to the earpieces. Without a useful signal, the two connecting leads have a clear transmission. If signal is applied, the effect is almost gone. The gold-plated stereo jack plug, which is wrapped in solid duralumin, is equipped with a protection against kinking and as a strain relief at the cable outlet. This is a first-class solution.

Inner Values

On the driver side, Fostex continues to rely on the proven 50 mm drivers of the TH900, i.e. neodymium magnets with a 1.5 Tesla magnetic flux density and a “Biodyna” membrane for the mk2. The membrane consists of bio-cellulose fibres with low specific weight and higher elasticity. The aim is to achieve a 2-fold higher propagation speed and a 5-fold higher rigidity compared to conventional drivers based on plastic film. The high flux density promises an immense dynamic range, the membrane quality a balanced frequency response and additional agility in the highs. The frequency range is given as 5 – 45,000 Hz, which isn’t unusual in the price range, but always an impressive specification to see. Due to the selected impedance of 25 Ohm, the headphones can easily be used with a wide variety of feeders.

Sound Experience

The basic sound of the TH900 mk2 is powerful, warm, bass-accentuated and rich in treble. The sound stage is surprisingly wide and airy for closed headphones. You get a wide, vivid picture that brings you closer to the recording situation, particularly in the case of live sessions. The converters have a skilful translation with a fine breakdown, even with very dense mixes. The liveliness enriches the listening experience substantially and encouraged me to rummage through many of my “listened to” productions again.

As with many current top models, the sound tuning is slightly V-shaped. The extended bass range plays itself into the foreground with tracks containing bass. Sound mapping reaches very far down and impresses with solid “punch behaviour”. At higher listening volumes, the low bass blurs a little and has a slight booming effect. Otherwise, EDM, hip-hop and R&B benefit from rich, extended and superior linear bass response. Roughly speaking, the lower and middle mids are also warm and present, whereas the upper mids to middle highs are more restrained. To sum it up, the TH900 mk2 offers a warm, multi-layered basic tone range and a less transparent present range. With that, vocals and string instruments are somewhat pushed to the back.

The upper highs, however, received a bit too much attention for my liking. As always, this is a matter of personal taste, the many highs simply proved tiring for my ears. As such, I found myself reaching for the volume control or hitting the pause button.

5 years ago by Marcus Schlosser
  • Rating: 4
  • Sound
  • Handling
  • Price/Quality
  • Function

I kept the Fostex TH900 mk2 for a week longer. On one hand, I found that the apparent problem areas of the transducer improved a little over the test period (habituation or better tuned transducers?). On the other hand, the liveliness led me to some additional sessions.

Fostex scores well with the TH900 mk2 in its league. However, due to the limitations outlined above, it won’t be achieving first place.

Measurement Results

Frequency response:

Exterior noise damping:
More measurement results

Technical specifications

  • Ear couplingOver-ear
  • Typeclosed
  • Transducer principledynamic
  • Frequency response (headphones)5 - 45.000 Hz
  • Impedance24 ohms
  • Sound pressure level (SPL)99,24 dB
  • Pressure averaged from big and small head515 g
  • Weight with cable518 g
  • Weight without cable390 g
  • Cable length320 cm

What's in the box

  • Headphones stand ST300
  • Cable with jack (3m)
  • Carrying pouch

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