Fostex TH900mk2

Disclaimer

Thanks to Mega Audio for loaning me this unit for the purpose of this review.
I have no financial incentive for making this review, all the opinions expressed are my own.

If you don't like reading, here is a video version of this review

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Intro

8 years after it's release and at just over 2000 Euros, the TH900mk2 still sits comfortably on Fostex’s dynamic driver headphone throne.

Inside can be found one of their 50mm biocellulose drivers and on the outside is quite simply, one of the best looking finishes of any headphone ever made; wooden cups with a coating of red urushi lacquer.

It took me a while to get around to it, but I first auditioned this headphone at High End Munich this year.

As previously mentioned, this is an 8 year old headphone, and since 2016, not only have I sampled my fair share of other flagship tier headphones, but have read reviews and forum posts that have been echoing the same thing for years: these are the widely accepted basshead king of the headphone world.

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Build, Design & Ergonomics

In the box you get the headphone, an owners manual and brochure, a very soft protein leather draw-string carry bag and something I’d love to see more of from other headphone manufacturers – a headphone stand.
It appears to be a very simple painted MDF construction with no anti-scratch feet on the base, but it is finished well, elegant in its simplicity and fits the design of the headphone functionally and stylistically.



I won’t bore you with an extensive analysis of the headphone.
The build is excellent.
The ergonomics are above average.
The fit is a touch wobbly, as clamping pressure is looser than average.
Headband comfort is about average. I do get a hot-spot in the middle at the top of my head after a few hours – I found that shortening the headband a notch increases the clamping pressure around the ears, may help alleviate this problem.
Weight is reasonably well distributed, but a slightly tighter clamp or improved headband padding might be better to fix the hot-spot problem.

The cable is a very thick fabric weave, but has higher flexibility than other similar cables.
The length of the cable has always been insane.
Not only that, the length of the Y-split is far more than I’ve ever seen before – it actually reached below my navel.
They also use a proprietary 2-pin socket, that looks like Sennheiser, but is actually not compatible with Sennheiser cables.
They are technically compatible if you force them in, but Sennheiser pins are spaced further out by 0.4mm, which is enough to risk causing damage to either the headphone or cable and something I cannot condone.

The extra large plug housing is a welcome feature, and an example that I think other companies should follow.



I’d give the ear pads a low passing grade.
At this price, I’m not super happy to see protein leather, but with a simple twist-lock system they are extremely easy to replace or upgrade.
Also on the plus side, they are moderately cavernous and should fit most ears. Despite their ordinary round shape, they are softer than average and easily provide a solid bass seal.

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The Sound

Going back to my first taste at High End Munich, before I put them on I was of course full of expectations and biases.
I put on my bassiest test tracks and knew instantly that the hype was real.

The TH900mk2 is able to render the deepest, tightest, cleanest and visceral bass without booming, diffusing the texture or bleeding into the midrange.
One thing of note that I don’t think I was ready for was the narrow soundstage.
I think I was expecting staging something a bit bigger than the Beyerdynamic DT770 Pro, but I didn’t get that.

Instead I got something even better and more important.
An extremely accurate stereo image.

That imaging, in combination with the fast, clean presentation, extremely high level of detail and absolutely flagship tier separation, I can’t help feeling like they’re the most high-end studio monitor on earth, except someone left the sub-woofer turned on high volume, making them extremely fun and energetic.

If I’m completely honest, the TH900mk2 is not even that bassy.
The bass shelf is only a mere 8dB higher than most of the upper midrange and treble.



Objectively and subjectively it manages to never steer too far away into bass hell and incredibly retains a subjectively accurate timbre that works very well for almost any genre I’ve tried.

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Amping

These scale very well, but crumble a bit with weak amps.

Out of my Fosi Audio SK01, complex recordings occasionally became mushy and less defined, while my audio-GD NFB11.28 TCXO on high gain brought out significantly more texture and detail specifically in the bass.
Even going into low-gain mode on the audio-GD, the bass clearly wasn’t as defined.
I would recommend feeding these as much power as is reasonable.

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Music

One of the most demanding pieces of music I could throw at this headphone is ‘BFG Division’ by Mick Gordan.
Finally. A headphone worthy of this masterpiece.
It actually made me want to reinstall Doom.
No other headphone I’ve ever tested with this piece of music can correctly render the appropriate level of thunderous slam.

Another good example is the opening bass line on ‘Mamabacore’ by Infected Mushroom which has never before sounded so layered and absolutely authoritative.
Then on ‘Doin’ it Right’ by Daft Punk, when the bass notes hit, and you’re expecting the 3rd bass hit to be quieter than the first two; it isn’t. It hits with just as much authority which is truly beyond satisfying.



To keep things fair let’s talk about the negative.

The treble is spicy.
On paper that doesn’t appear to be the case however it manages to be more piercing than almost any other studio headphone I have heard, except the DT770 250 ohm.

Two pieces of music I like to test treble with are ‘Creep’ by Radiohead where the cymbals in the chorus are particularly sharp, and ‘Bangarang’ by Skrillex which is frankly quite poorly mastered and it very shrill up top. Neither of these are a joy to listen to with the TH900mk2.

Then while trying to enjoy the dropped tuning of the bass guitars on KoRn’s 'Freak On a Leash', I was unfortunately distracted by this hissing treble on the vocals.

I was expecting a similar story with ‘Playing God’ by Polyphia, but the TH900mk2 somehow towed the line incredibly well, while also proving it’s ability to render natural instrument sounds incredibly well.

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Gaming

I couldn’t help firing up some Quake 2 RTX and was both shocked and relieved to hear that the incredibe imaging accuracy I heard in the music translated perfectly to positional cues in video games.
Of course, it also helps to have an awesome heavy metal soundtrack playing in the background.

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Comparisons

I now want to make some very quick and dirty comparisons, but focusing only on the bass.
Red = Fostex TH900mk2
Green = Comparison headphone

I have to say, there's something special about testing some of the best bass oriented, closed-back headphones on earth all at once, and I’ll be a little bit sad to see this one go.

In case anyone was wondering how something like the Hifiman HE-500 compared, there was no competition.
Even the HE-500 which is known for having excellent planar bass reproduction can’t compete and also exponentially crumbles with more and more bass boost.
Of course, in many other aspects, high-end open backs always win, but that’s not what this is about.

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Conclusion

The TH900mk2 is stunning.
I don’t think there is even a very specific target audience for this type of sound.

The overall tonal characteristics are well within acceptable average limits, the objective resolution is among the very best there is for any dynamic headphone, and the medium-sized staging combined with the pinpoint stereo image is utterly captivating.

Ultimately, I cannot give these a strong pass due to the outdated headband with it's comfort issues and the difficult-to-stomach price.
However, there aren’t many modern masterpieces, but this I count among them.