Fostex TH909 Review

Fostex TH909

Sound Quality

Because the TH900mk2 lent its ‘Biodyna’ drivers to the TH909, I was bracing myself for a lively (bordering on fatiguing), rambunctious V-shaped roller-coaster. But, surprisingly, this really isn’t the case here at all. Opening-up the earcups really has given the TH909 its own, distinctive signature. It’s actually quite a natural-sounding and fairly even-sounding headphone while still managing to be exciting and aggressive, at times – when you let it off the leash. The TH909’s timbre is on the lean side but has enough extension and emphasis at either end of the frequency graph to remind you that these are definitely not a ‘neutral’ pair of headphones. 

It’s a natural starting place to compare the TH909 with its closed-back counterpart, so let’s establish what makes them different, for starters. The TH900mk2 has fairly prodigious levels of bass quantity, a little too much for my preferred signature to be honest. I’ve always enjoyed listening to the bass on the TH900mk2 as a bit of a ‘guilty pleasure’, but that’s only been with borrowed pairs in small doses. I find that the TH900mk2 isn’t always able to correctly articulate lower notes in terms of speed or finesse, and it can sound a little flabby or wooly. So colour me impressed when Roon decided to serve-up Pink Floyd’s ‘Young Lust’, and the TH909 showed itself to have perhaps the most linear and accurate bass response I’ve heard in an open back dynamic headphone. The TH909 reaches impressively deeply and nimbly dispatches bass notes with crispy leading edges and natural decay. 

The next pleasant surprise as the TH909’s mid-range. For starters, it actually has one! Jokes aside, the TH909 is almost mid-forward – particularly the upper mids but it’s neither honky nor unnatural sounding. Fostex has tuned this headphone in such a way that it gives the most vivid reproduction of human voices and instruments – tonally, these are clear-sounding rather than rich or syrupy. Bob Reynold’s excellent live album ‘Guitar Band’ can make or break a headphone in terms of how convincing it can be at recreating live music. The TH909 convinced me that it was more than up to the task, and stunned me with the most realistic-sounding saxophone reproduction that I can recall hearing.  

In terms of treble, the TH909 is a bright headphone but it’s not what I’d call hot – which the TH900mk2 very much is. I prefer a brighter sound signature, and these float my boat in that they have almost more detail and edge than you think you can manage, and then reel it back in ever so slightly. They’re definitely an exciting, and engaging listen. 

So, has taking the sides off the cups made them crazy-open sounding? Not hugely, to be honest. There’s no ‘concert-hall’ presentation with crazy wide staging à la the Sennheiser HD800s, but the TH909 does reward with an impressive ‘out-of-head’ experience thanks to its ability to place a drum hit here or a brass note there into an unexpectedly realistic 3D space. The TH909’s sense of imaging is pretty impressive, its ability to throw left/right panned drum notes not only left and right, but also forwards, backwards and upwards in Tool’s ‘Aenema’ is seriously cool. 

Fostex TH909

Fostex TH909

TH909 vs Focal Clear

These are two extraordinarily well-matched headphones and make for a great head-to-head comparison. The Clear comes in a couple of Benjamins cheaper than the TH909 and obviously forgoes the handmade aesthetics, but it still manages to convey the Focal brand’s understated opulence in its terrific build. Going from the Fostex to the Clear is an unusual experience – the Clear sounds almost ‘polite’ compared to the bigger, more forward and aggressive-sounding TH909. There is markedly more sub-bass quantity in the TH909, as well as a much more pronounced highest octave. Tonally, the biocellulose drivers of the TH909 sound ‘wetter’ and more organic, while the M-profile Aluminium/Magnesium dome drivers on the Clear reveal a more metallic, drier voicing. Ultimately the TH909 makes for a more coloured and engaging listening session, while the Clear is a subtler, more nuanced and linear experience. I’ll give the comfort nod to the TH909. 

TH909 vs Sennheiser HD800s

The HD800s has a noticeably larger (bordering on exaggerated) sense of soundstage width compared to the ‘helmet’-like stage of the TH909. The Fostex flagship bests its Sennheiser counterpart for bass quantity and quality and presents an overall warmer sound compared to the lean, airy HD800s. The HD800s takes the cake for micro detail and ultimate transparency but lacks the TH909’s fun + engagement-factor.   

TH909 vs Audio Technica ATH-ADX5000

The Audio Technica open-back flagship is the logical competitor for the TH909, and sets a very high bar indeed as I established in my review. The ATH-ADX5000 is a lighter, airier headphone – both in terms of build and comfort and also in the way it translates music. The TH909 is definitely the pick for those looking for a warmer low-end ‘punch’ and a more dramatic overall delivery, whereas the ADX-5000 schools the TH909 when it comes to width, space, and separation. The ADX-5000 has greater detail and transparency, but it’s definitely on the spicier side in terms of treble. Sometimes a little too spicey, depending on what mood you’re in. 

Fostex TH909

Fostex TH909

TH909 vs Final D8000

Final’s D8000 might be both much more expensive than the TH909 and feature planar rather than dynamic drivers, but being the flagship open back offering from another Japanese audio house it feels relevant to compare them. Plus, I just so happen to have a pair with me at the moment. Tonally, the two headphones couldn’t sound more different. Whereas the Fostex is all drama and detail, the Final is laid-back, dark and smooth. The TH909’s snappy, quick low-end makes the D8000’s sound like butter and treacle by comparison – it really is like a velvet sledgehammer. The TH909’s upper midrange feels even more pronounced back-to-back with the D8000, with some voices sounding a little tinny/breathy by comparison. The TH909 doesn’t need much by way of volume to wake it up and start performing, but for the same given volume, you feel like you still need to crank-up the D8000 more to extract the excitement out of it. The D8000 is all about smokey refinement and the absolute absence of distortion, whereas the TH909 just lays the party out there on the table. 


The 25-ohm impedance/100dB mW TH909 is easy to drive, and not taxing in terms of power requirements. Its form-factor and long, heavy cable make it most appropriate for desktop or HiFi listening but the TH909 also performs superbly with portable equipment. The Astell&Kern SA700 got Beck’s ‘Lonesome Tears’ up to adequate listening levels at 80/150 on the volume pot, with superb grip and control of the bass notes, and nice vocal tone and texture. As expected, the Chord Mojo is also a fine pairing with the TH909, its naturally sweet character proving to be a nice match for the TH909’s lean treble tilt. 

Switching over to the same Beck track on the Questyle CMA Twelve DAC/amp resulted in a wider, more realistic soundstage as well as a richer midrange, which benefited from the added tonal heft. My favourite solid-state pairing for the TH909 turned-out to be the Schiit Asgard 3 + Bifrost 2 stack. Having close to 5 watts per channel running into the single-ended Fostex cable seemed to really agree with the TH909 in terms of creating the smoothest, most organic tone with plenty of dynamic punch when called for. I was pleased to find out that the TH909 liked being fed with tubes, in this case, the Hagerman Tuba. using the low-impedance output of the Tuba, the TH909 did get a little looser in the bass (in a somewhat enjoyable way, like it’d had four beers), but the sweetening it gave to the treble department more than overcame this, as it shaved off any lurking hint of a hard edge. That pair of Mullard EL34’s really played nicely with the TH909, and not surprisingly I stuck to tubes for most of my time with them.    


The Fostex TH909 is a curiously interesting headphone. Firstly, it’s somewhat curious that it evem exists in the first place, being a not-that-open take on the not-that-closed TH900mk2. However, the TH909 turns out to very much be its own headphone sonically and not just a ‘chop-shop’ TH900mk2 custom mod. It’s also a much more interesting choice compared to its contemporaries in its price bracket, which opt for much ‘safer’ tunings and of course, offer nowhere near the visual flair of the stunning Urushi cups of the TH909. 

I found that the tuning of the TH909 makes it a versatile match for a number of different genres – there’s never a boring moment when you’re listening to these. The TH909’s bass doesn’t disappoint when called-on to play Run The Jewels ‘RTJ4’; and it’ll give a stunning account of itself a minute later with both Bon Iver and Taylor Swift on the track ‘Exile’ from her newest album ‘Folklore’ (which, I might add, is pretty good). 

So, why might you buy the Fostex TH909? If you’ve been looking for the perfect, safe pair of flagship headphones that do most things well, then perhaps you shouldn’t go safe at all. Perhaps you should embrace a bit of flair and own something that was made by hand from a real person, and designed to excite all the senses. At a time when things feel increasingly more ‘disposable’ (even $1,000+ headphones), the TH909 feels very much like a ‘zagger’ – and something you’re probably going to want to hang onto for a long, long time. 

4.3/5 - (48 votes)

Hailing from Sydney's eastern beaches, Matty runs his own beer business, 'Bowlo Draught', as well as working in creative advertising. When he's not enjoying his hifi and vinyl collection at home, he can probably be found rolling-up on the green at his beloved Bondi Bowling Club.


  • Reply September 1, 2020


    Any chance you could review and share your expertise on the Hifiman Arya ? I’ve been waiting a long while for Headfonia’s take on it.
    Thanks – An Avid Follower

    • Reply September 2, 2020


      Arya was another version of the Edition X/Ananda of which we covered 3 already. So we decided not to review it right now.

  • Reply September 3, 2020


    honestly the 909 looks more like a ferrari than any other headphone with that beautiful grill

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