Fostex T50RP mk4 Review
No, the Fostex T50RP mk4 is not a hyperactive hard rocker. Rather, it wants to present itself as an elegant studio professional for all relevant tasks and also convince critical listeners.
The Fostex T50RPmk4 is an orthodynamic professional headphone that, due to its semi-open design, is suitable for all stages of music production and undoubtedly offers high-end sound.
BY HARALD WITTIG
There’s a lot happening in the headphone segment at the Japanese manufacturer Fostex: After the sinfully expensive and extremely good high-end headphones TH1000RP and TH1100RP, Fostex has also added much more affordable models to its headphone lineup. This includes our test candidate today, called the T50RP mk4, which presents itself changed not only externally compared to its still available predecessor, the T50RPmk3.
Above all, it differs technically—we’ll cover the essentials later—from the older model. For that, it is also significantly more expensive: At around $345, the T50RP mk4 is priced. The T50RPmk3 is already available for $193. Whether the T50RP mk4 is worth the significant extra cost, we will clarify in this test. Before we start, an important note: On the Fostex website, a variant of the headphone is offered, called T50RP mk4g, which, it seems, is optimized “For Gaming.” In fact, it’s merely a marketing gimmick: It’s the same headphone; only the name and packaging were changed. The reason: The T50RP mk4 became, in the shortest time, the favorite of Japanese gamers—which the marketing strategists at Fostex want to profitably utilize. So don’t let yourselves be confused. There is only one T50RP mk4, which we now want to examine.
Completely Redesigned Drivers
The T50RP mk4 is an orthodynamic headphone in a semi-open design, which is generally rare. In magnetostats, also called orthodynamics, this construction is as rare as Martian dust. Basically, the design is a good compromise for a studio headphone that is to be used versatilely for recording, mixing, and mastering: These headphones have better isolation to the outside, so that microphone recordings—keyword: crosstalk—are feasible. At the same time, semi-open headphones—provided the manufacturer knows their craft—can approach the sonic balance of open designs. This is why the T50RP mk4 could have what it takes to be an all-round tool in a production.
To ensure that the playback also meets the requirements of audio professionals, Fostex has equipped the headphone with a completely redesigned fourth-generation RP driver. “RP” stands for “Regular Phase,” and admirers of Japanese engineering may think of the hi-fi cult brand Accuphase. There, the name also stands for highly precise reproduction without coloration. Accordingly, Fostex’s RP core technology is supposed to guarantee particularly accurate reproduction that we need for the meticulous sound assessment during production.
For this, Fostex has devised a new printed coil form to enlarge and linearize the vibration range of the ultra-thin flat diaphragm. Additionally, the number of neodymium magnets enclosing the diaphragm has been increased. Furthermore, the magnetic circuits in the current version of the RP drivers have been redesigned to optimize the distribution of the magnetic flux, suppress distorting resonances, and achieve better transient response. In the end, these new drivers offer higher sensitivity, a more linear frequency response, and an outstanding transient/impulse behavior.
In any case, the newcomer boasts a significantly extended frequency response compared to the previous model: In the lows, the T50RP mk4 reaches far down into the bass cellar. It is supposed to reproduce ten hertz—that’s very good—but is still surpassed by some dynamic studio professional headphones. We think, for example, of the dynamic DT 990 Pro and DT 1990 Pro from beyerdynamic, which can descend very deep into the bass darkness, namely down to five hertz. That is mentioned here only for the sake of completeness. Because the sub-bass range of the T50RP mk4 is undeniably remarkable and suitable for reproducing sub-bass sonic events.
Conversely, the magnetostat should also be able to ascend into bright heights: At the specified 40 kilohertz, things get quite bright, and even if there may be competitors that at least on paper go even higher, the Fostex is in the best company with the established top players among professional headphones. Especially since impulse response, resolution, and linearity are far more important to us than a bit more high-frequency sparkle or bass rumble.
Fits and Wears Well
We are very pleased with the comparatively low impedance of only 28 ohms and an increased sensitivity of 97 dB/mW. Because this means the Fostex can also be operated on headphone outputs with lower output voltage. Indeed, it sounds very good on most audio interfaces with the T50RP mk4 without having to crank the volume into the critical, i.e., noisy, area. The higher sensitivity favors a loud, yet distortion-free reproduction compared to less sensitive headphones.
Besides these sound-critical innovations, Fostex has also given the T50RP mk4 a new, uniformly elegant black housing. The newly shaped ear cups have a centrally placed connection jack. The thankfully single-sided cable can be plugged into either ear cup as desired. An unwanted channel swap is not to be feared. This has advantages for left-handers and is also welcomed by musicians who prefer to throw the cable over the shoulder while playing to be unimpeded. The fact that there is no bayonet lock doesn’t bother us. The cable sits very firmly and securely in both sockets.
The connection cable is a two-meter long, high-quality OFC cable with 3.5 mm jack plugs. Optionally, symmetrical cables with 2.5 and 4.4 mm jack plugs as well as XLR connectors are available. So those who swear by symmetrical operation with their high-end headphone amplifier for sound reasons can retrofit. But that’s not exactly cheap: The prices range from just under $110 to $121 for the XLR cable.
Not so good: The gold-plated adapter is not screwed on but simply plugged in—and based on our experience, it likes to get stuck in the amplifier’s socket. There’s a faintly printed minus point for that. Moreover, Fostex could have included a second cable with its not exactly cheap headphone. Otherwise, there’s nothing to complain about with the copper cable: It seems stable and is neither too stiff nor does it threaten to tangle quickly.
On the other hand, we really like the design of the ear pads: They are covered with synthetic leather and consist of “memory foam” that adapts excellently to the wearer’s ears. This feels extremely pleasant, and indeed, we don’t start sweating even during very long listening sessions. The wearing comfort is further enhanced thanks to the self-adjusting headband. It automatically adjusts to the head size. The fine-tuning still has to be done via the guide rails on both sides, which are fairly smooth to adjust. But once it is set, the headphone can be put on at any time, and the wearer greets it with a convinced “Welcome home.”
Unquestionably Studio-Suitable
The workmanship is solid and offers no cause for complaint. Mainly, high-strength plastic is used, while, for example, the guide rails are made of metal. But frugal fare is on the menu when it comes to accessories: There’s not even a carrying pouch. We wish for more there. After all, the T50RP mk4 is a headphone in the $345 class.
But ultimately, wearing comfort and, above all, the sound of the headphone remain decisive. That’s why we now put on the Fostex and want to explore its sound with alert ears. To ensure the signal chain is optimally forged, we feed the T50RP mk4 various material through our proven reference combo. This consists of the Mutec MC3+USB as an audio interface connected to the MacBook Pro. Via AES/EBU, it goes into the Mytek Stereo192-DSD DAC and from there analog into our two high-end headphone amplifiers: Via XLR into the Violectric HPA V280 and simultaneously via RCA into the HPA V200 from the same manufacturer. As the first title, we listen to the lesser-known ballad “Nightmare” by the McAuley Schenker Group from the acoustic EP of the same name.
Guitarist Michael Schenker plays the lead parts with an Ovation, which he plugged directly into the mixing console. The guitar sound is therefore characterized by the treble-rich piezo pickup system of the instrument. Even good headphones like to suppress this typical high-frequency fizz. The Fostex, however, does not let itself be fooled and presents the guitar melodies in a detailed and finely resolved manner. Even our tried and true AKG K702 Studio cannot do better. On the contrary: In direct comparison, it falls behind the Fostex at least in terms of treble reproduction. Although, in this discipline and in terms of plasticity, the Fostex finds its master in the Dan Clark Stealth. However, the Dan Clark plays in a completely different league—also in terms of price—because the high-end headphone costs $4,950.
So let’s leave the unfair comparison and state as objectively as possible that the T50RP mk4 is a really good magnetostat. It always delivers detailed, quite naturalistic images of the audio material. For example, when listening to a Logic Pro project, it represents the special high-frequency sparkle of a miked Fender ’65 Deluxe Reverb and the successful digital emulation in the form of the Combo Deluxe ’65 pedal from TC Electronic as well as the fine digital replica in IK Multimedia’s Amplitube 5 very well. Other magnetostats from the hi-fi corner in the same price range tend to sound more beautifying and dampen the treble while at the same time pushing the lower mids to the forefront.
As expected, the Fostex is hardly unsettled by basses of any kind. Thanks to its responsiveness, i.e., very good impulse behavior—the inherent strength of magnetostats—combined with the extended low-frequency range, bass assessment is effortless. The well-coupled and balanced midrange follows and completes the overall linear reproduction. The spatial representation is very good, although in this discipline we still prefer the dynamic Focal Listen Professional (test in issue 04/2024). But others might perceive it differently, as the differences are not aurally obvious in this respect.
Also on the headphone outputs of audio interfaces and converters such as a UA Apollo X8 or our trusty Mytek Digital 8×192 ADDA, the T50RP mk4 can be profitably operated. Even on the headphone output of the Combo Deluxe ’65 pedal, so we were effortlessly able to set our sound for the test recordings by ear with the help of the Fostex. Finally, the Fostex is also suitable for enjoyment listening, because high-resolution audio material can be presented by the elegant professional from Japan thanks to its playback competence at top-class level. Then it can also gladly be the Hi-Res edition of the AC/DC classic album “Back in Black.” So that you may rock forever and very gladly with the T50RP mk4.
The two-meter-long OFC connection cable is single-sided and can be plugged into the left or right ear cup according to preference. There is a
T50RP mk4 Specs
I’ll generate the table in a copyable text format for you:
Type | Magnetostatic
Headphone |
Color | Black
Weight | 330 g
Price [RRP] | $345
Technical Data |
Transducer Principle | Magnetostatic/Orthodynamic
Design | Semi-open
Frequency Range | 10 Hz–40 kHz
Magnets | Neodymium
Impedance | 28 ohms
Sensitivity | 97 dB/1 mW
Max. Input Power | 3,000 mW
Connection Cable | 1 x 3.5 mm jack, single-sided
Scope of Delivery
2 m cable, 6.3 mm jack adapter, quick start guide, symmetrical connection cables (optional)
Special Features
Fundamentally redesigned fourth-generation RP drivers, self-adjusting headband, OFC connection cable optionally pluggable to left or right.
Evaluation
Category Upper class
Features 8/10
Wearing Comfort 9/10
Build Quality 9/10
Sound 9/10
Overall Rating 9/10
Conclusion
The Fostex T50RP mk4 is a professional magnetostat that is suitable for almost all stages of music production thanks to its semi-open design. It gets many things spot-on and needs to fear only competitors that are many times more expensive—including those from its own company.
• Very good impulse response and an overall balanced, finely detailed sound
• Very good efficiency
• High wearing comfort
• Robust construction
• Reasonable price-performance ratio
– Few accessories included in the package
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