The Fostex Orthodynamics: T50RP and T40RP Mk2


Given the high level of popularity of orthodynamic headphones among the local crowd, I’ve had multiple chances to audition Fostex’s orthodynamic headphones, including several different versions of the T50, as well as the different damping variation mods on them. But this is the first time I’ve had a chance to listen to the T50RP at the convenience of my home set up, as well as the T40RP Mk2, which I’ve never auditioned previously. Thanks to Hiroaki at Fostex Japan for sending me the headphones for this review.


Despite the saying that vintage Fostexes are better than the newer versions, I have to disagree and say that the T50RP is in my opinion the best orthodynamic Fostex has made so far. Signature to this headphone is the grainless, smooth, and deep black background evident in its presentation. In brief comparison, I don’t think any of the older T50 versions have a sound as grainless and as smooth as the current T50RP model. The smooth and grainless sound is very similar to the way the LCD-2 sounds, except that obviously you’re not going to get the LCD-2’s bigger and more three dimensional soundstage and its powerful bass. The T50RP’s smooth and grainless sound is very electrostatic like, except that the T50RP feels far more closed though the overall sound is weightier than the Staxes, which tend to be light on the bottom (Lambda frames, mostly). In comparison to say the Hifiman orthos, the tone is noticeably different, as the Hifiman has a grainier sound, and more dynamic-like in that regard.

The T50RP is not the typical headphone that I would recommend to the average listener. First of all, it was meant to be a studio monitoring headphone, along the likes of Sony’s MDR-900ST, Shure SRH-840, and Audio Technica’s M-50. Though the tonality is somewhat similar to those three headphones (say compared to a Beyerdynamic DT880 or a Sennheiser HD650), the Fostex T50RP gives the most mid-centric sound as the treble and the lower bass sounds noticeably more laid back, especially when compared to the Audio Technica M-50. If the Shure SRH-840 and the Audio Technica M-50 remains to be fairly popular among us music listeners, the Fostex T50RP is like a niche headphone in an already niche segment of closed monitoring headphones. Though the T50RP Fostex has gained quite a reputation for somewhat being a “hardcore enthusiast” headphone in my local forum, I think that in reality, the sound signature of the T50RP still remains somewhat a niche in that it’s not going to get the popular following of the Audio Technica M-50, the Shure SRH-840, or the Sennheiser HD25-1.

The housing size is fairly big. Here are a size comparison with the Fostex TH-7B, Audio Technica M-50, and the Fostex T40RP Mk2. The T50RP is identical in housing size to the T40RP Mk2.


Now that you’ve gotten an idea of where the T50RP stands roughly in the big headphone landscape, I’m going to tell you why this headphone is worth owning, because somehow, within the limitations of the T50RP, it doesn’t prevent me from getting drawn to the sound of the headphone.

As I said earlier, the T50RP is about a smooth grainless sound, and a deep black background. You’re not going to find a sparkly treble, punchy tight bass, or a massive soundstage with this headphone. If you find it difficult to understand what a grainless sound or deep black background is, it’s because they are rarely mentioned in headphone reviews. Indeed these are minor things we’re talking about (compared to tight punchy bass or a deep soundstage), but the Fostex pulled it off so successfully that I can’t seem to get enough of the T50RP’s sound. To put things into perspectives, dynamic drivers are almost always grainier (even the Sennheiser HD800) than what you get with the T50RP. Some of the less grainy dynamics are the Audio Technica M-50 and the Ultrasones, but the average Beyerdynamics, AKG, Audio Technica, or Sennheiser headphones are always grainy sounding cans. I don’t know if this is a function of the T50RP driver simply being better hence less grain, or if it’s the case of the Dynamic driver resolving grain in the source and amplifier (I’ve listened to the HD800 out of a Lehmann Black Cube and a Blacknote 3000 CD Player and it was quite grain free. Likewise the HD800 out of the Manley Neo-Classic 300B amplifier is very grain free). Nevertheless, the grain free sound is something that I rarely experience out of a dynamic set up, but the Fostex manages to give it to me on any set up I use.

The same grain-free and black background sound can be found in most Stax models (though I find the original Stax Lambda to be slightly grainy, likewise the original Fostex T50v0). When comparing the T50RP to the Stax Lambda frame models, obviously the closed circumaural T50RP feels noticeably closed than the Lambdas, but on the other hand I find the T50RP’s sound to have a more proper weight on the low end as well as a more linear midrange-treble area than the Staxes. Although the Lambda frames ultimately would sound more luxurious and spacious (hence a typical Stax Lambda system sells for more than $500), the Fostex again remains quite unique in itself, and I can see how some people would prefer the Fostex to a Lambda system.

Both models come with the same driver.


The other side of the driver.


The T50RP was made to be a supposedly flat-line studio headphone, and although most dynamic headphones voiced that way tend to be flat and boring, the T50RP’s unique voicing is one of the most addictive headphones I’ve ever auditioned. It’s the headphone that makes me want to stick around my headphone testing room and play one more song just to hear them out of the Fostex.

Due to the relatively flat tonal balance, you’re not going to get the kind of pleasing coloration that you’d get from say a Sennheiser headphone, or the sparkly treble and clarity out of a Beyerdynamic. The PRaT factor is also moderate, as each bass punch is just enough to tell you that the microphones have indeed captured them. Worth mentioning is the way the treble smoothly extends to top frequencies, making a very relaxed listening experience while still maintaining a good extension. But the most special aspect of the T50RP is its presentation of the vocals. Good presence and intimacy, but the T50RP’s moderately relaxed stance keeps the vocal in an unoffensive stance, making for a very relaxed long term listening session. The mood is just perfect for Indie stuff like Mumford and Sons, Belle and Sebastian, or She and Him. Any music with a cool and relaxed attitude seems to play very well with the T50RP, and as of now it may be the best headphone I’ve found for listening to Beatles’ Remastered albums. When I try playing alternative Rock with the T50RP, I feel that the attack on the music has been numbed and the snap a little rubbery. Although it makes for a quite unique presentation, I would gladly recommend something like the Alessandro MS1i or the Sennheiser HD25-1 as you get a better attack and energy on those cans.

Removable cables with locking mechanism.


T40RP MK2 vs T50RP

The T40RP mk2 is a closed design model, also equipped with an orthodynamic driver. Positioned as one model below the T50RP, it’s similar to how the Sony ZX700 is to the Z1000. However, the drop in sound quality of the T40RP makes it a hard model to recommend to you guys. First of all the bass rolls off quite early and is not as deep as the T50RP. The midrange is also less composed, less weighty, and more honky than the T50RP. Overall the sound is clearly inferior and not as well composed as the T50RP. The housing reverbs are also more evident on the T40RP, adding a small amount of plasticky timbre compared to the T50RP. Well, at least the bass is not as boomy as what I remembered the T20RP Mk2 to sound.

Surprisingly all these difference comes from a simple differences in the housing. The T50RP’s drivers have openings on the slots, where the T40RP Mk2’s totally closed. Another difference is a slight change of damping material positioned right behind the drivers.

Both Fostex orthos are relatively efficient and easier to drive than the Hifiman and Audez’e full size orthodynamics. An Ipod can do a decent job, but a Hifiman HM-601/602 have more than enough voltage swing for these orthos, likewise a simple entry level DAC/Amp box like the Audinst HUD-MX1.

Surprise, surprise. Same driver!


The slots are semi open on the T50RP. They are fully closed on the T40RP Mk2.


Differences in damping: pay attention to the small piece of felt cloth around the middle of the housing. This is the T50RP’s housing.


And this is the T40RP Mk2’s housing.


OTHER COMPARISONS (vs Audio Technica M-50, vs Fostex TH-7B)

The tonal balance and sound signature of the T50RP is very flat and unoffensive. This is a far as you can get from typical colored headphones like the Grados or the dark and laid back Sennheisers, and even the AKGs and the Beyers are not as flat sounding as the T50RP. When choosing for a headphone to compare the T50RP to, a headphone that come to mind is Fostex’s own TH-7B, a dynamic driver with similar voicing to the T50RP. Another one that I can think of is the Audio Technica M-50, a fairly linear dynamic headphone if we overlook the bass areas that sometimes get a little boomy.

In the dynamic world, the Audio Technica M-50 ranks fairly low on PRaT factor, as other less technical headphones like the Marhall Major or the relatively unknown Sennheiser PX90 easily does better PRaT than the M-50. However, with the Fostex T50RP, PRaT was totally non existant that it makes the fairly laid back Audio Technica M-50 a better Rock headphone when seen relative to the T50RP. I do not mean to attack the T50RP with that statement, but rather, I try to describe some of the principal differences between the two phones. Here is a headphone that presents all of the frequency ranges with such an inoffensive attitude that the M-50 can be seen as an agressive headphone when compared to the T50RP.

In the area of soundstage, the T50RP gave a much wider and deeper soundstage than what I’m hearing on the M-50. The three dimensionality was quite flat, and in that area the M-50 is better. But overall, the bigger soundscape, the more distinct separation, and the more laid back soundstage makes it a better tool for monitoring purposes or for playing live recorded Jazz. The relaxed presentation also makes it a better Jazz headphone than the M-50, though overall the M-50 is the more all-rounder headphone.

The voicing of the T50RP is also quite close to its dynamic sibling, the TH-7B that I reviewed earlier. But again the dynamic driver made a less flat presentation with a fuller bass body and a more evident upper treble that makes cymbals more lively. Though the soundstage is not as wide as on the T50RP, the TH-7B presents a deeper and more three dimensional image. Though I am a big fan of three dimensional soundstage, in this case my ears still prefer the T50RP by a significant margin. One reason is the more accurate timbre, but the midrange of the T50RP simply is better to my ears than the TH-7B’s.


Hopefully I’ve done a good job in giving a picture of what the T50RP and T40RP sound is all about. Between the two models, the T50RP is definitely the one to go for. Both are fairly niche headphones, and rock listeners better stay away from them. However, I do think that there is a strong magic in the sound of the T50RP, and it’s definitely a very unique headphone that I would recommend to Jazz, Vocals, and Indie listeners.

The Fostex Orthodynamics: T50RP and T40RP Mk2
5 (100%) 2 votes

  • Alex

    Thanks for Fostex review, Mike! Can you say T50RP is the best for voice on the market comparing even to HD800, other modern ortho?

    • Anonymous

      Hi Alex, by voice you mean vocals right? It certainly is good for vocals, and it has its own uniqueness in the vocal presentation, but I wont say the best in the market.

  • Katun

    Nice. I remember when I bought that headphone and had my first listen. I almost cried, wishing I would have bought it as my first headphone — so I wouldn’t of had to spend all that unnecessary money on headphones I didn’t like as much. In other words, it’s one heck of a headphone for the money spent for it. I just wish the comfort was a bit better, mainly deeper and more comfy earpads that allow better ergonomics to the head as well as your ear not flat against the driver. Other than those nit picks, It’s a fabulous headphone, especially for the price.

    By the way Mike, you take fantastic pictures. On par with your reviews! 😉

    • Anonymous

      Thanks, Katun. 🙂

  • Niko Adrianus Yuwono

    Nice Review Mike, but I think I’ll still trying to make a TP because my friend give me a good offer. Maybe I’ll let you try the TP before I sell it to my friend.

    • Anonymous

      Allright man. Thanks.

  • Brian


    Did you get the chance to use the HP-P1 together with the T50RP?

    I am thinking of getting a HP-P1+T50RP combo and as you have reviewed both products, you are the man to ask about them.


    • Anonymous

      Yes, I did. It is a nice pairing, and I’d recommend it, as long as
      you’ve read the description on the T50RP’s sound and think that it is
      the right headphone for you.

  • Steve

    Mike, I think you nailed this one. For the price, if you can live with the trade-offs, it’s a no brainer (at least here in the states). I would love to hear the Thunder Pants version.

    • Anonymous

      Thanks Steve,
      Yes it would be nice to do an article on the Thunderpants isn’t it?

  • it’s unique when you say t50 rp is not for rock music. In the last 6 month. i paired it with SSMH and gamma1, and this setup definitely for rock 🙂
    Maybe you should try another setup to convince you that T50RP is a right headphones to  play the rock music 😉

    • Anonymous

      Are you getting a punchy bass out of that SSMH and T50RP because I doubt
      you do. The SSMH is quite polite in the bass and likewise the T50RP. I
      think bass like the HD25-1’s is truly needed for Rock.

  • Arthur

    Hi, I’ve had my T50rp for about 3 years now and really like their sound signature – especially with older recordings. 
    Recently I’ve acquired an HD 650 and was very surprised to find them a tad too bright with slightly recessed mids. This is contrary to what I’d though they’d sound like a after reading peoples reviews and posts. 

    Between the Audeze LCD-2 and Hifiman HE-500 (or perhaps a different one) which headphone sounds closest to the T50rp – but with better bass/treble extension and more open soundstage? One that can match the beautiful full midrange of the T50rp’s or even exceed it 🙂

    (I listen to a variety of genres but mostly classical, jazz, electronic and rock)


    • Anonymous

      Yes, it’s funny. The T50RP is actually darker than the HD650, and the
      HD650’s upper mid is not as forward as the T50RP. It’s just that the
      HD650 has been known all these time as a dark headphone, and it’s hard
      to change that branding.

      If you prefer the frequency balance of the T50RP, I think you’ll find
      the HE-500 to be too bright for you. The LCD-2 will be more or less same
      in terms of treble brightness/darkness, but the mids is not as present
      as the T50RP’s. The bass and treble extension will be better on both the
      Hifiman and the Audez’e than on the T50RP. The soundstage is more open
      on the HE-500 but more three dimensional on the LCD-2. The mids of the
      LCD-2 is closer sounding to the T50RP, but the mids of the HE-500 is
      better than both of them. 🙂

      The LCD-2 works great with Electronic and Rock. I think the HE-500 is
      better for classical and slow and acoustic Jazz. The LCD-2 sounds more
      closed than the HE-500 and with live recordings like Jazz and Classical,
      I think the reverbs in the sound (somehow like what you hear on closed
      headphones) really gets in the way of the sound. The HE-500 is not a
      perfect classical headphone, but I prefer it over the LCD-2 for Jazz and

  • Arthur

    Yes, to my ears the T50RP sounds a lot darker than the HD 650. I do like the HD 650’s, just wish their mids were a little more forward. Perhaps the HE-500 will solve this. 

    • Anonymous

      Yes the T50RP is definitely dark.

  • Bert

    Louis from Audiohub does magic with these headphones and 8 ASI Sugar Cubes. It is like the Thunderpants mod, but minus the need to change a lot of things.

    • Anonymous

      That’s very interesting, Bert. Thanks for sharing with us.

  • Nick01

    Hi Mike,
    Do you know where I can buy this? I’m in Australia and can’t seem to find any retailer.

  • Gräza

    Hey! Got any good suggestions regarding dac/amp or seperated dac + amp for the T50rp? Around the 200-300 $ region.

    • Anonymous

      I think the DACport would match very well with the T50rp, but it’s slightly above $300 ($399 I believe).

      If you want, you can also opt for the Audinst HUD-MX1:

      The DACport has a punchier bass and I think that’s good for the T50rp. The Audinst is more dark/mellow, and so personally I would prefer the DACport to get a livelier sound out of the T50rp.

      • Gräza

        Thanks for the reply! 🙂  How about the Yulong u100 ? Do you think that would have good synergy with the fostex t50rp ??  Seems like it after reading your review…

        • Anonymous

          Yes, the U100 has a good synergy with the T50RP, but please read the comments section of the Yulong regarding some people’s comments on compatibility. That’s why I haven’t been recommending the Yulong as often as I did anymore.

          • Wäzi

            Sounds good, last question now!! Would the uber muzik tiny tube dac have good synergy with the fostex t50rp you think? Uber muzik tiny tube dac is really tempting for me !! :O

            • Anonymous

              I think it would be a good pairing, though I personally think a pure solid state is better for the Fostex T50RP.

            • Anonymous

              I think it would be a good pairing, though I personally think a pure solid state is better for the Fostex T50RP.

  • Donunus

    has anyone compared a stock t50rp to a t20rp?

    • Anonymous

      I don’t think anyone has done a proper comparison. From what I remembered, the T20RP is much looser on the mids and bass, and feels a little hollow in the mids. The T50RP is more linear and controlled. But that’s just from two separate impressions, so I can’t say, and it seems everyone these days have modded their T20RP.

  • deanreed

     After doing a little research, it seems like there is an amazing amount and variety of modding going on with the Fostex T50RP. I’m really not interested in modding so, I wonder:  Is it right to assume that you enjoy these stock, as-is? 
    Also, do you think these would match up OK with my Schiit Asgard? Thanks as always.

  • Theguatemalian

    Did this article dissapper the description has a lot in it but the actual article is missing.

    • We’ll look into it. thanks!

  • Stew

    Hi Mike,

    I’ve been investigating some of the mods done to these headphones (TR50Ps) and there appears to be a guy with initials LFF who does a great job and may even be willing to do the mods for others. I hope I am not overstepping any bounds by asking if you have any idea how one might get in touch with this fellow; I have been unsuccessful in locating contact information, anything other than those initials! So sorry if this is an inappropriate question on your blog!

    • Hi Stew,
      I don’t mind at all, and I would’ve given you his contacts but I don’t have it. However you can get in touch with boilermakerfan/Brian Elgin. He’s one of the best out there when it comes to orthodynamic damping mods.!/brianelgin

  • Stew

    ps I believe the mod in question is called the Paradox.

  • Joe

    Hi Mike,
    Would pairing the T50rp with the ZO2 improve the bass and treble presence ? Maybe turn it into a better all-rounder?
    Would PRaT improve?

    • Joe,
      I wouldn’t recommend it. The T50Rp is not the type of headphone that you pair with the Zo.

  • Kenny Tan

    Hey Mike,

    I just bought the T50RP (out of curiosity) and haven’t opened it yet, in case I may want a refund. To help decide whether I should open it, do you think the T50RP makes a good match with my CMoyBB (straight out of Ipod Nano, unfortunately), or should I just return the T50RP to save myself money?

  • Kenny Tan

    Hey Mike,

    I just bought the T50RP (out of curiosity) and haven’t opened it yet, in
    case I may want a refund. To help decide whether I should open it, do
    you think the T50RP makes a good match with my CMoyBB (straight out of
    Ipod Nano, unfortunately), or should I just return the T50RP to save
    myself money?

    • Kenny,
      I just tried the pairing and I think it works fine.

      • Kenny Tan

         Thanks for the quick reply and for personally testing it.

        Out of curiosity, did you do any mods on your T50? If you did, can you mention which ones?

        • I didn’t personally do any mods on my T50. My friends do though, all sorts of damping stuff that seem to evolve from one month to the next. 😉 I still prefer the balance of the stock T50 than the modded ones.

  • San3

    Hi Mike,

    Nice review of the two Fostex headphones.
    Of all the following headphones: Superlux HD-330,  Fostex TH-7B and the Fostex T50RP, which one (or two) do you recommend (amped of course)? 

    • Hi San3,
      Each of the three headphones have their own plus and minuses. What are you looking for?

      • San3

         Thanks for the reply, Mike. Well, I like a large, airy soundstage (3D) and seperation of instruments so I can focus on just one instrument. I would like to add another candidate to my shortlist, the Superlux HD668B.

  • Hey Mike, how would the T50RP do when paired with the E10?

  • how is the comfort (clamp , clasp , pressure) on the T50RP ?

    the TH-7B are pressing on my ears too much.. cant use them more than 2 hours straight..

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  • Roy

    Would it pair well with the Pico power amp?

    • I haven’t gotten the Pico Power, sorry

    • Sorry Roy, haven’t tried the Pico

  • mike, to me the t50rp sounded very bad. i havent used it for a while but it just sounded so weird… cavelike, honky, and hollow, those are the words that some people have used to describe them and i dont know better words than those… im probably hearing it like how you hear the t40rp

    • Yes the T50rp has an awful housing reverb issue. People like the smooth sound and clean transients.

      • Jonathan Yeung

        Mike you are right and I paired it with the dx100 for the first time yesterday without expecting much and it sounded pretty good, I noticed the honkiness once in a while but not that big of an issue. The thing I appreciate the most about it is it doesn’t give me fatigue like my sony z1000 or my Beyer dt990. Have you tried this pairing Mike?

        • No, not the dx100. But yes the Fostex is fatigue free

  • Ahmed Hikmet

    Hi Mike,
    What about those FOSTEX T50RP for listen only Classical Music on Cowon without ampli ?
    Does the Th7bb sound very natural compared to the T50rp?
    Thank you very much, from France.

    • Please add an amp, even a simple one like the nuforce MMP I find to work great for the T50RP.

      And yes the T50 is more natural than the T7Bb

  • Kevinjit

    Hey, wanna ask, the combination of FOSTEX T50RP with a tube amp, is it a good pairing?

    • Depends… it sounds good with the Studio Six. 😉

  • dav ep

    I’m considering the 40s or 50s for use in an office environment. I’d like as little sound leakage as possible. From all accounts the 50s are better sounding, but being semi-open would imply they would be louder to people nearby. How disturbing would you say they are?