Review: Fostex TH900
originally published on November 25, 2013
revised & re-published on December 29, 2013
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download a printable 10-page PDF version of this review (target goes to a location on my Dropbox)
(click for larger photo)
Intro
I first heard the Fostex TH900 at CanJam@RMAF 2012 in October, which was a costly mistake.
It was one of the most promising headphone auditions that I've ever had at an audio show, enough that I was persuaded to impulse-buy my own pair on Black Friday 2012 when they were being discounted by Moon Audio. I no longer own the TH900 though and sold them earlier this year in August for personal reasons, but I couldn't let my experience go without writing something about them, so here we are with my completed full review.
Apologies for the length of this review (at 10 pages printed) to those who find it too long, but there was so much that I wanted to share and not much that I wanted to delete. And given the high price of the headphones, I felt that such a long review was merited.
Equipment Setup
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Source component: Plinius CD-101 (CD player) (Signal Cable Silver Reference power cord, directly into wall)
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Analog interconnects: Emotiva X-Series RCA on GS-X MK2, X-Series XLR on BHSE
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Headphone amplifiers: Burson Audio Soloist, HeadAmp GS-X MK2 and Blue Hawaii SE
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Headphones: Audio-Technica AD2000, HiFiMan HE-400, MrSpeakers Mad Dog 3.2, Stax OII MKI
Evaluation Music
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Alison Krauss & Union Station -
Paper Airplane
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Carlos Kleiber & VPO -
Beethoven 5 & 7
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Erin Boheme -
What Love Is
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Goldfrapp -
Black Cherry
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Helloween -
7 Sinners
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In Flames -
The Jester Race
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Julia Fischer -
Bach Concertos
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Kamelot -
Poetry for the Poisoned
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Lee Morgan -
Tom Cat [AudioWave/Blue Note XRCD]
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Massive Attack -
Mezzanine
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Nicola Benedetti -
Fantasie
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Ruth Moody -
The Garden
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Steve Kuhn -
Mostly Coltrane
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The Crystal Method -
Tweekend
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The Prodigy -
The Fat of the Land
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Trifonic -
Emergence
Foreword
This review contains my usual “lexicon” of audio descriptors that I'm well aware may not be easily understood by all readers. Some words may be confusing, others will lack apparent explanation and/or context, and most of it will just likely be foreign to those who haven't heard a variety of headphones and won't understand what I'm trying to convey. Nothing in this review is purposely meant to confuse or obfuscate though, and I'll just say this: all lexicon used is my best attempt to try to explain the “sound” of audio using the written word, which is extremely difficult to do, if not impossible. Much in the same way as the phrase “a picture is worth a thousand words” holds true, so too “a sound is worth a thousand words” as well, and there are no words period that can accurately convey everything that I perceived from the Fostex TH900. My standard recommendation for all readers is this: try to find an opportunity to hear the headphones for yourself, or just buy them (new or used)—at worst you can easily re-sell them on Head-Fi if you don't like them.
Since the words “natural” and “neutral” are used throughout my review, I'll define them upfront:
- “Natural”: Meant primarily as the opposite to “unnatural” or “fake”, because of the headphones that have sounded unnatural to me for one reason or another. Unnatural-sounding headphones to me include: most Audio-Technica headphones (due to weird tonalities), most Grado headphones (due to sucked-out mid-range bands), AKG K70x (due to weird spikes in treble & mid-range), and the HiFiMan HE-400 & Sennheiser HD800 (both due to an emphasized treble & thin mid-range). Headphones that have sounded “natural” to me include: Stax OII MKI, Grado HP1000, Sennheiser HD600, Audeze LCD-2/LCD-3, and Beyerdynamic T1. For me “natural” means a tonality & timbre that makes most acoustic instruments sound reasonably close to that of real-life counterparts, instead of making them sound “fake”. Additional info should be provided here as well: I've been a violinist since age 6 and know the sound of a violin intimately (I'm 32 as of this writing), along with that of the piano and several other orchestral instruments. So when I listen to music, I seek headphones that can hence reproduce “non-fake” instrument tonalities.
- “Neutral”: Technically, “neutral” should mean “flat”, or a flat frequency balance across the board from bass to treble, but few headphones actually execute that. So I've since discarded that idea in favor of baselining headphones that actually sound neutral to my ears, and to me these headphones do: Stax OII MKI, Grado HP1000, JH Audio JH13 (IEMs). All other headphones that I've heard are non-neutral to me, though some have gotten surprisingly close, specifically the latest models of the Audeze LCD-2 r2. I'll repeat:
all other headphones are non-neutral to me. A full list of headphones that I've heard is in my Head-Fi profile.
Please do not send me any PMs in regards to this review, as I won't respond to any unsolicited PMs for personal reasons (this is repeated in my sig & profile).
Sonic Summary
I'll say it upfront to get it over with: the TH900 was easily hands-down one of the best dynamic headphones that I've heard to date, closed or open. It was superbly natural-sounding (note: not necessarily neutral-sounding, because it wasn't), but what spooked me most about it was how close it got to the level of the Stax OII MKI. I thought it was by far the closest-sounding pair of dynamic headphones to the electrostatic Stax OII MKI, indeed so close that when I sold the OII/BHSE (for reasons unrelated to the TH900), I didn't miss the electrostatic system that much.
I'd sum up the TH900 as an open-sounding mid-range-oriented headphone (not that “mid-range-oriented” should mean “warm” though, at least as “warm” is typically used by other reviewers), with a deceptively surprising bass attack. I'd further describe it with the following list of qualities:
- Uncharacteristically open-sounding for a closed headphone, similar to the Audio-Technica W5000 in solely that aspect. Very diffuse-sounding with a lot of openness/airiness throughout, preventing anything from sounding close-up and presenting a large hall- or stage-like sound—not overly spacious, but not compacted either. Somewhere in-between those, skewed slightly more towards spacious.
- Low-hitting, powerful, & driller-like bass. Light on overall quantity to really fill out the 30-80Hz area, and even less in the 80-200Hz mid-bass area, but with the hitting force of a jackhammer for that 30-80Hz area. In short, the TH900 had a sneakily forceful low-bass kick that dominated over the general mid-bass “impact” zone (i.e., contrasting from something like the Audeze LCD-3, which has high mid-bass impact).
- Well-balanced sonically with a very natural tonality throughout—appropriately natural-sounding enough to make most acoustic instruments sound reasonably close to realistic, from string to jazz instruments.
- An overall U-shaped, scooped-out mid-range despite the natural tonality—i.e., the mid-range lacked body & fullness to an extent, primarily in the lower mid-range and mid-bass area. This negatively affected especially male vocals and instruments like bass guitars, so the TH900 wasn't ideal with music that used one or both of those components (in my case that was metal, but it could also apply to heavy, hard, and progressive rock).
- Mid-range with a bold, vivid, rich character, not too far-off from certain discontinued Audio-Technica wood-lacquered headphones that I've heard in the past like the W5000 and W2002. Very “expressive”-sounding too, with a distinct inflection that especially added to plaintive-sounding music & instrument techniques (like long violin bowstrokes). This also contributed to making certain female vocalists sound somewhat lascivious, depending on the vocalist's style/range—it was more noticeable on female jazz vocalists in particular (Erin Boheme being a good example of it from my own CD collection).
Breakdown
The summary above provides a big-picture context of the TH900 for this review, but of course there were further aspects of the headphone that both positively added to it and negatively subtracted from it. I'll start with the positives:
+
Light weight and comfort: Headphones have to be comfortable in addition to subjectively sounding good, and fortunately the TH900 was very comfortable to wear. They were nicely light-weight and the headband was curved just right to distribute the weight evenly across my head instead of creating any singular pressure points, unlike the HE-400 and bumped-headband versions of the AKG K70x which were very uncomfortable to wear for long periods of time. The earcups were fully circumaural as well and didn't exert much clamping pressure.
+
Low leakage & low isolation: Leakage & isolation are tricky to balance on any headphone—they're not necessarily advantages to everyone in all situations. For example, someone looking for closed headphones might want as much isolation as possible to block out the environment, or as little isolation as possible so that they can listen to music while not being completely unaware of their environment. I thought the TH900 struck a decent balance between leakage versus isolation. At low to moderate volumes it didn't noticeably leak much sound, though if your intended purpose is to use them nearby other people within ~10 feet or less, I'd advise not cranking up the volume, because high-volume sound can easily leak out and be audible within a short distance range due to the relatively light clamp. It was two-way as well, so the isolation level was also low—i.e., it was relatively easy to hear background noise from a TV in another room with the headphones on, for example. Those who want more isolation should consider another pair of headphones or IEMs.
+
Mid-range-oriented sound: This has already been pointed out but it bears repeating. The TH900 wasn't exactly subtle about adding various inflections and sonic “colors”—in fact, it was probably one of the more sonically-colorful headphones that I've heard. It added extra character to vocals and a sort of “glare” quality to brass instruments that enhanced reediness and bronzy characteristics, but just a little. Nothing that was too much, but it certainly made genres like jazz sound more colorful & flashy. Perhaps a negative aspect but I personally enjoyed the inflection, as it seemed to enhance certain kinds of music.
+
Open, spread-out sound and large soundstaging: The TH900's open sound can't be overstated either, it was just remarkably open/diffuse/airy for a closed headphone, with a width & depth surpassed only by the even more open- & diffuse-sounding Sennheiser HD800. The TH900’s soundstage was a bit smaller-scale than the HD800 though, which I considered a good thing, as I view the HD800's soundstage to be too over-the-top large. In terms of only the soundstaging, I might liken the TH900 more to the AKG K70x—wide & deep, but not overly so. However, lest that provide the wrong idea, unlike the AKG K70x, the TH900 positioned everything in the mix distinctly out & away and very nicely spread-out, for a good illusion of music playing in a wide, airy space.
And now for the negatives:
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Lack of sonic agility: The TH900 wasn't a very agile-sounding headphone and was downright clunky-sounding on fast music, especially in the bass/mid-bass area. It didn't “spring” from one note to the next and seemed to overhang a bit, which made it sound like it was dragging weight. It was borderline ponderous-sounding, which made no sense given its electrical characteristics (25 Ohms and 100 db/mW). I thought it should have been a lot more agile-sounding given its low-impedance spec.
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Short decay: This wasn't unexpected for a closed headphone, as every closed headphone I've heard has a short decay, it just goes with the territory. This affected mostly my enjoyment of ambient electronica, which relies on properly long decay to deliver the effect—i.e., sonically-disappearing layers should slowly fade away back into the background and shouldn't be cut off at the end. The TH900 cut off these “exit trails” as I call them, which made it sound sort of flat.
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Lack of focus & insistency: The TH900 was also “unfocused” to me, as if it lacked a sense of forward-moving drive. This was most noticeable on fast music, or fast note sequences. There was no “insistence” or “momentum” to its sound and in some cases it sounded as if it were bored & listless, almost inert, and it wasn't motivated to metaphorically start running. It was a stark contrast to my Audio-Technica AD2000, which has the opposite characteristic and always sounds like it wants to immediately tear down the nearest racetrack at breakneck speed.
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Lack of dynamic range at the extremes: The TH900 had a decently wide musical dynamic range, more than some of its competitors like the Audeze LCD-2/LCD-3 and Sennheiser HD800, but not as much as the even-more-dynamic Stax OII MKI. I've previously likened the Audeze models to have a musical dynamic range that goes from mezzo-piano to mezzo-forte, and using the same scale I'd say the TH900's dynamic range went from pianissimo to fortissimo (
pp to
ff), but not pianissimo possibile to fortissimo possibile (
ppp to
fff). The only headphones I've heard that have the
ppp to
fff dynamic range are the Stax OII MKI when amped by the HeadAmp BHSE. Granted, the TH900 had good dynamics on its own, but it just wasn't as wide-ranging as the Stax OII MKI's and lacked proper handling for both quiet and intensely loud volumes—i.e., quiet parts lacked a certain subtlety, and extremely loud parts lacked sheer tear-off-the-ceiling intensity. It simply didn't handle low volumes that well and typically sounded better moderate to loud.
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Lack of soundstage depth: As mentioned above in the positives under “Wide, open sound and large soundstaging”, the TH900 set up a clear stage-like presentation, but it set up everything on that stage at the same apparent depth position. Not with multiple depth planes to provide the illusion that certain instruments were behind (or in front of) others, like the Stax OII MKI was able to do. Admittedly sort of a nitpick, as most dynamic headphones lack this ability too, but it was still noticeable on very critical listening sessions.
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Lack of neutrality: The TH900 wasn't neutral compared to the OII MKI (which many do consider neutral, me included), and as already mentioned, it had a scooped-out mid-range leading to a sort of U-shaped frequency response. Although the mid-range was only minorly scooped-out, it was still enough to me to detract from my enjoyment of some genres like metal, which often relies on male vocals to sound heavy and/or aggressive, and the TH900 was never able to convey that.
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Limited multi-genre applicability: Already implied above, but for most people the TH900 may not be ideal for all genres due to its sonic signature. While some may find it perfectly acceptable for classical, like I did, some others might not. Still others might find it acceptable for rock & metal, or electronic music, but I thought the TH900 didn't do quite as well in those genres. Either way, even for me the TH900 wasn't the master of every genre and only handled a few really well (classical, jazz, acoustic in general), so I'd imagine that others would find the same results.
Informal Comparisons: Audeze LCD-2 & LCD-3, Sennheiser HD800, Fostex TH600
Unfortunately I didn't own the TH900 alongside the HD800 and Audeze headphones simultaneously, so I can't provide a direct comparison. I can only provide an “informal” comparison that loosely relates the TH900 to each headphone based on my previous experiences, going off memory. First, it should be noted that I heard the HD800, LCD-2, and LCD-3 on various amps, not only in my home but also at various Head-Fi meets and shows (like CanJam@RMAF). Second, not all of these headphones have the same amping requirements, and an amp electrically optimal for the HD800 isn't necessarily also optimal for the Audeze headphones, and certainly not optimal for the TH900 too. That doesn't even consider the sonic characteristics of such an amp, which can further skew the results. That said, here are the informal comparisons:
Audeze LCD-2/LCD-3: The Audeze LCD-2 & LCD-3 have a basic tonal similarity to the TH900 (i.e., they all have a “natural-sounding” mid-range) but are fundamentally different, and neither of them are necessarily “better”. I consider the LCD-2 and LCD-3 to sound a lot alike, so I'll lump them together and simply say that they both have suffocating soundstages in contrast to the open-sounding TH900—that is, their soundstage has always sounded overly compacted regardless of the amp, and despite being open headphones, they both almost sound like closed headphones with everything placed too close-up and not having enough breathing room in the virtual space. The Audezes both also have substantially more relative bass & mid-range than the TH900, particularly the LCD-3, which I consider especially bassy & full-sounding. But to get the big-picture view, to me both of the Audezes have a fantastically physically tactile and assertive sound, very American-style in their assertiveness, and with quite an upfront quality about them. Compared to them, the TH900 is a lot less physical-sounding, with a more general passive and distant sound, but on the flipside provides bigger spatials and more clarity.
HD800: I consider the TH900 and HD800 to be more different from each other than similar, though both have large-ish soundstages. I think they're sonically complementary and fill in for each other's weaknesses to an extent. The HD800 has always lacked mid-range to me regardless of the supporting gear, and even on the best amps that I've heard it on, which include the Luxman P-1u (at home) and Apex Teton (at RMAF), it's still always lacked a perfect treble-mids-bass balance to me. For me the HD800's best qualities are its treble (even though it's a little too emphasized relative to the mid-range) and its high level of clarity. Although some view the HD800's open & large soundstaging to be one of its highlights, I'm not one of those people, as I think that aspect of it is a little too over-the-top and it's an unnatural effect on most genres of music. So for me, the TH900's smaller-scale soundstaging and higher mid-range quantity, along with its more-powerful bass, make it more musically versatile, as I was able to enjoy more genres on it, especially bass-oriented electronica which I could never listen to with the HD800. The HD800 was always genre-limited for me and the only types of music that I could tolerate it with were ambient electronica, bluegrass/folk, and generally female vocal-based acoustic music (blues, jazz). With the TH900, I could tolerate all of those genres plus more, namely instrumental & period jazz which was another intolerable genre for me on the HD800 due to its thin mid-range.
TH600: My report on the TH900 versus TH600 is linked below under “Related Reading”, as I got the chance to have them in-house together earlier this year thanks to the HeadAmp Demo Program.
Even-More-Informal Comparisons: Audeze LCD-XC, MrSpeakers Alpha Dog
It's perfectly ok if most people completely discount my informal comparisons to these two headphones, as I wasn't even sure about adding them myself for the simple reason that I only briefly heard the LCD-XC and Alpha Dog at this year's CanJam@RMAF. But I ended up deciding that it's probably worth giving these new-release headphones a short comparative mention. So I also have to add the usual caveat: my experience with the LCD-XC and Alpha Dog so far has been solely in a show environment with uncontrolled variables and less than ideal conditions.
First, as stated before, there are very few amps that will functionally drive the LCD-XC, Alpha Dog, and TH900 equally well, and that's not even considering the sonics of such an amp. With the sonics factored in, there are definitely no amps that will drive all 3 headphones perfectly. So with that said, here are the informal (and speculatory!) comparisons. Take them with extra grains of salt!
LCD-XC: The physical aspects should be factored in first, because Audeze headphones in general have been big & heavy with a lot of clamping force, and it seemed that the LCD-XC was especially bulky & heavy. Sonically I might consider the LCD-XC to be darker than the TH900 with less of its finesse and subtlety and more of that classic Audeze sound—more physically tactile and even more forward & assertive than the existing Audeze models, almost borderline aggressive. The LCD-XC also seemed to be quite closed-in-sounding, with even more of a compacted soundstage. It had more mid-bass quantity too—probably just the right amount for most bassheads, I'd imagine. So I don't view it as being very similar to the TH900 and more like a contrast as something different. The LCD-XC is probably a better headphone for those who like electronic, pop/rock, and/or metal—or just generally “American Top 40” types of music, because it is an American-made headphone, after all. I even saw Alex Rosson (the president of Audeze) DJ-ing at RMAF 2013 using the LCD-XC.
Alpha Dog: I think the TH900 is probably a natural upgrade from the Alpha Dog due to sounding more open & diffuse (separated), with more clarity as well. The Alpha Dog is more neutral though, since I found its tonality to be surprisingly close to the Audeze LCD-2 r2 when I directly compared them at RMAF on the same amp (I consider the LCD-2 to be relatively close to neutral). For those who might already be stretching to afford the Alpha Dog and are wondering if the TH900 is worth stretching further for, I say just buy the Alpha Dog. It's an incredible value at its price and the TH900 isn't a huge landslide improvement over it, plus the Alpha Dog is closer to neutral which makes it more musically versatile. But for “cost no object” buyers, I think the sonic advantages of the TH900 relative to the Alpha Dog make it worth the purchase for its more-open soundstage (with more air & diffusion throughout), tonal richness, and overall finesse at handling various musical subtleties, especially those in classical music. Moreover, those who want a “large-scale” soundstage for classical music would probably do well to skip straight to the TH900. Finally let's not forget, the Alpha Dog is planar magnetic and the TH900 is a low-impedance sensitive dynamic, which means that they have very different amplification requirements. A good high-voltage amp needs to be factored in for the Alpha Dog while the TH900 can be easily driven by anything with a headphone jack (though it benefits from proper high-current amplification).
Direct Comparison: vs MrSpeakers Mad Dog 3.2
The only reason for this comparison was because the Mad Dog and TH900 are both closed, even if the two headphones are different types (the Mad Dog being planar magnetic, and the TH900 dynamic) and vary wildly in price. That said, the Mad Dog is a great budget closed headphone that's not really comparable to any other closed headphones up to $300, unless we count the KEF M500 which goes in another sonic direction completely. Perhaps I should just say that the Mad Dog and M500 are two different sides of a coin and are both highly recommended for those on a budget. That is to say, if you buy one and don't like it, then the other would probably sound better to you since they're close to polar opposites.
The TH900 was closer-sounding to the Mad Dog than the M500 overall, but it took the Mad Dog formula and improved on it significantly. For one, it was way more efficient, obviating the need for a high-voltage amp (but a high-current amp would naturally be useful). The TH900 was basically like a much more open-sounding Mad Dog with a more relaxed, laid-back sound, slightly thinner bass (but no reduction in low-level depth & force), and more refined treble. That covers the “basics” but there was also much more subtlety to the TH900 that can't be succinctly put into words. Suffice it to say that I thought the TH900 was a definite upgrade over the Mad Dog.
Direct Comparison: vs Stax SR-007/BHSE
The TH900 got awfully close to the OII MKI, much closer than any other headphones that I've heard. What made it so close to the OII was its combo of an essentially open, clear sound and a natural, rich tonality that added quite a bit of color & expressiveness to its sound. Though the OII wasn't colorful or expressive on its own, that added quality of the TH900 helped it to get closer to the OII's level of performance on my system. Without it, the TH900 would've had quite a bit less going for it. That said, I almost could've considered the TH900 (along with the GS-X MK2) as a dynamic replacement for the electrostatic system completely and not have missed much other than some really subtle musical details that the OII MKI brought to the table. It's only for that proverbial last 1% that the OII MKI eclipsed the TH900. The electrostatic setup simply transcended typical headphone limitations to provide something unbelievably surreal-sounding.
There was the TH900's non-neutral mid-range too, contrasting from the perfect neutral balance of the OII MKI. It also had less treble extension than the OII MKI and sounded less precise. However, one of the most noticeable contrasts came about from the fundamental difference between closed versus open headphones—the TH900 didn't really have a black, silent background and its note decays were consistently cut-off, as previously mentioned above. With that exception, the TH900 had more genre versatility than the OII, mostly thanks to its added bass (because that's sort of a lacking aspect of the OII MKI). It was more adept at electronica & metal than the OII MKI, while still being great for classical. It could have been even better for classical though if its dynamic range was wider, closer to the level of the OII MKI's, but it was still very acceptable, if not completely ideal for very quiet or very loud music.
For those interested in the minutiae, I've included detailed info on how the TH900 compared to the OII MKI in the Notes section below.
Amplification
I was able to test the TH900 on only two amps, the Burson Soloist and HeadAmp GS-X MK2, so I can't really speak for how it might sound with any others. But I can say that the TH900 requires a proper high-current amp to sound its best given its electrical characteristics, and it sounded very good on the Soloist, and great on the GS-X MK2. I recommend trying other amps though, as I'd expect that there are probably plenty of others that would pair even better with it.
Conclusion
If there's one thing that I want readers to take away from this review, it's that the TH900 was awesome-sounding but not perfect either. No headphone ever is, and even the Stax OII MKI had its flaws to me, though admittedly the OII MKI had the fewest number of flaws that I've ever found with a headphone. But for me, the Stax OII MKI was the closest that I ever got to sonic perfection—it was positively amazing and life-changing, and reaffirmed to me the potential of high-end headphone audio.
That's not to say that I can't say the same about the TH900 though, because it too was amazing. Even with all of the other headphones that I've heard, I consider it one of the top dynamic flagships currently in production! The mere fact that I could compare it to the Stax OII MKI for this review (and that it came away with its dignity intact) is high praise for it, especially when I haven't found any other dynamic or planar magnetic headphones that can remotely compare to the OII MKI's level.
I say buy it if you can afford it and then be happy, because this hobby is full of endless pursuits and for most people it won't be worth it to keep going further for a high-end electrostatic system. For those who honestly want the truly best-sounding, cost-no-object headphones, go ahead and skip straight to a Stax OII MKI w/ BHSE. But for those who value their time & money (and their energy bill, because the electrostatic system soaks up tons of wall power), go for the Fostex TH900 instead. It simply offers high-quality sound and is worthy of being one of the “final” set of headphones for anyone.
Related Reading
Audeze LCD-3 mini-review:
http://www.head-fi.org/t/594426/mini-review-audeze-lcd-3-vs-lcd-2-r2-sr-007-et-al
Fostex TH600 micro-review:
http://www.head-fi.org/products/fostex-th600-dynamic-headphones/reviews/9723
Addendum – Review Notes
My review notes are included here in their own section for convenience. These provide specific detailed info not included in the review. Not all listening data was documented either, this is only a fraction of the total listening that was done (much more listening was done than the notes might indicate). Lastly, the review was not written directly from solely these notes, this is only provided as a supplement. Notes start below the asterisks.
***
TH900 vs OII MKI
Massive Attack -
Mezzanine,
Goldfrapp -
Black Cherry,
Alison Krauss & Union Station -
Paper Airplane,
Ruth Moody -
The Garden,
Helloween -
7 Sinners
- OII's imaging has more center-fill and sounds more “continuous” and “integrated”, TH900 more divergent to left and right. TH900 lacks OII's “swift lightness” and sounds heavier/clunkier, very obvious on percussion (i.e., belly drums on “Inertia Creeps”). TH900 also partially blurry in mid-bass/mid-range. OII's lightness/”spring” works for it a lot more, while TH900's clunk works against it. TH900 lacks blinding-speed percussive impact of OII and AD2K—lacks that hard- & fast-hitting aspect. TH900 is “hard” but not completely “fast”. Recovery specifically is slow; lingers too long. Very slightly “plodgy” or “rounded-off”.
- TH900 sort of like a darker OII—less treble quantity, more mids, deeper & heavier bass. Also slightly smaller-scaled in the soundstage. OII soundstage more “organized”. OII still has more clarity and cleaner treble as well—actually substantially more clarity. Even if mids make OII sound “thinner” than TH900, OII's clarity provides more “detail” on timbre & tone. TH900 has a slight tendency towards a “congealed thickness” and congestion, while OII does not.
- Bass: deep/full on TH900, satisfactory impact with moderate thickness as well. Very clear on OII, not as heavy/deep. Bass seems “faster” on OII than TH900. More “powerful” on OII though, as well as lower extension on it. OII more capable of producing low-extending, hard-driving bass when amped by BHSE. TH900 lacks extension and an aggressively “hard” drive into its bass range—i.e., TH900's bass notably heavy & deep but not particularly focused. Lacks the parallel focus/drive of OII.
- More air/spatials/separation/dimension on OII—more sense of soundstage depth & width. Can make OII sound “bigger” than TH900. TH900 more “intimate” than OII, vocals are pushed forward more (more in-your-face) and have less depth to them.
- OII has excellent low-volume integrity; TH900 not as adept. OII sounds just as good extremely quiet as it does loud, TH900 sounds better moderate to loud.
- TH900 otherwise very close to OII—probably closest-sounding dynamic headphone to OII, nearly an equivalent. There are no real dynamic equivalents to the OII—but the TH900 gets awfully & scarily close nonetheless.
Julia Fischer -
Bach Concertos: OII sets up more realistic soundstaging—not too close, not too far, just the right width span. Just the right spatials & separation too—excellent sense of the acoustic space, the sound waves reverberating throughout. TH900 lacks that aspect of the acoustics. TH900 also lacks the “radiating” sound of the OII and the pure/clean sound of Fischer's violin. TH900 a little bit “masked”, OII simply has purity of sound and maintains a beautiful purity to Fischer's violin. Specifically, TH900 masks Fischer's violin-bowing technique a little—volume modulation, string-crossing, etc. TH900 seems to have excessively “warm”-sounding violins, not an unpleasant addition though. Violin “wood” tone also spot-lighted on TH900, so they sound extra “woody”. TH900 also lacks fast, light Baroque touch that OII has.
Carlos Kleiber & VPO -
Beethoven 5 & 7: Unconvincing wall of sound via TH900—lacks coherency. Though OII has more “separation”, it's the TH900 that has a disjointed-sounding orchestra, with way too much space/distance between violin & cello sections. Depth planes not apparent on TH900 either—everything seems at same depth plane. TH900 doesn't project outwards very well and lacks the “air” that would make the orchestra sound larger. TH900 also has blobby-sounding violins—sort of a mess. Sections too “unified”, individual violins not distinct enough. OII has more volume intensity than TH900—TH900 seems louder because of more mid-range, but lacks sheer intensity that makes horns in particular scary-sounding. OII has more “projection” on the horns too so they seem more powerful.
Nicola Benedetti -
Fantasie - “Zigeunerweisen Op.20”, “Spiegel Im Spiegel”: TH900 lacks “subtlety” of OII—specifically in low-volume parts. TH900 has more of a bold, rich, vivid character while OII is capable of more of a subdued character, not quite as bold/vivid. TH900 makes Benedetti's long, wide bow strokes very expressive-sounding.
Steve Kuhn -
Mostly Coltrane - “Song of Praise”: Very full-sounding sax on TH900. Everything close/converged & full on TH900; OII divergent & thinner. TH900 has more of a “throw you in with the jazz group” effect, like Grado HP1000.
Lee Morgan -
Tom Cat [AudioWave XRCD] - “Twice Around”: fuller-, closer-sounding instruments on TH900 that add to more “presence” factor, like Grado HP1000. Guessing, TH900 not far from HP1000 in terms of texture? TH900 seems like a crossover of both HP1000 and OII—soundstage & texture of HP1000, clarity & tonality of OII.
TH900 vs AD2K
The Crystal Method -
Tweekend - “Murder”, “Over the Line”, “Blowout”: TH900 sort of like the sonic inverse of AD2K—U-shaped mid-range sinkhole contrasts to AD2K's bowed-out C-curve (more mid-range, less lower bass). Bass phase/pass stronger on TH900. In general TH900 has more sub-80Hz quantity than AD2K that contributes to it sounding bassier down low; however it also sounds thinner & more recessed than AD2K in upper mid-bass & lower mid-range.
In Flames -
The Jester Race - “Moonshield”, “Artifacts of the Black Rain”: Lack of mids on TH900 bothersome on these tracks; the guitars are highlighted too much in the treble and don't have enough mid-range thrash to counterbalance. Fuller sound of AD2K better for these tracks. Vocals also shoved too much to background on TH900, but not an issue on AD2K.
Kamelot -
Poetry for the Poisoned - “The Great Pandemonium”: Track distinctly boring on TH900 due to lack of mids and overall aggression. Much more “alive” on AD2K. Percussive hits shoved to background on TH900, very forward on AD2K.
TH900 lacks that “x-factor” that would make it truly awesome for hard-driving industrial/electronic/rock/metal. Lacks a “growl” or mean streak. However, definitely complementary to AD2K; opposite styles. AD2K is aggressive/forward, TH900 is passive/laid-back.
The caveat is that certain amps do make the TH-900 V shaped. Is that a problem? I don't think so. The V shape is a really good V shape, if you know what I mean.
Here is another reviewer that echos my findings:
https://www.samma3a.com/en/reviews/wooaudio/wa5-le-class-a-desktop-headphone-tube-amplifier-276.html
I think the TH-900 is the best closed headphone out there with the right amplification.