Fostex has been making headphones with durability, low (ish) impedance, high efficiency and an overall “fuller than brighter” sonic signature for quite some time. I’ve purchased numerous T20RP, T40RP and T50RP models over the years and even reviewed the newer T50RPmk2; as such, I’ve been curious about the new semi-open back, ear-surrounding T50RPmk3 studio headphone.
Its overall design is “all new,” yet familiar; its most obvious new feature is a short(er) red cable with an 1/8-inch stereo mini-plug with Fostex’s proprietary locking connector. This tabbed twist-lock is actually usable on the end that plugs into the sound source, but it is exactly the same as the other end that plugs into the left ear cup. The result is a reversible cable that remains useful even if the small twist-lock tabs should break off of one end. A standard stereo quarter-inch TRS terminated three-meter cable is provided, too.
Sonically, the new T50RPmk3 moves closer to flat in frequency response (15 Hz - 35 kHz) than previous T50 versions, though with a little more top end, more clarity and more neutral mids—although those mids do have a bit of color that is similar to previous T50. The new diaphragms are copper foil etched polyimide film via neodymium magnets.
Efficiency-wise, the T50RPmk3 comes in as “rather loud” at 92 dB (1 kHz at 1 mW) due to their 50-ohm low impedance, similar to other Fostex ‘phones. Such efficiency is quite useful, especially for those with low-output headphone amps found on many affordable interfaces today. They will handle 3W, thus can take hot levels, too.
Isolation-wise, the T50RPmk3 does indeed surround the ear but are semi-open, not with the deep recess cup like the Fostex T40; the result is more leakage coming in and no “total” isolation. I think that makes the T50RPmk3 a little more useful for vocalists and guitarists with an actual amp; and a little less useful for drummers who desire total isolation to get click up and over their loud playing (as relayed by session drummer Brian Burton while in evaluation of the review unit). In fact, every client that tried the 50RPmk3 liked it, preferring it over any older Fostex models I have at Catalyst Recording.
So, the new RP Series from Fostex is available in three flavors to especially suit the app: the T20RPmk3 (open backed, notably deep bass); T40RPmk3 (closed back, notably focused bass); and the T50RPmk3. The latter retails for $159, placing it squarely in the middle of the pro-grade headphone price pack. If efficiency, durability and an un-hyped bottom-end is desired for tracking, overdubbing and mixing, then the T50RPmk3 would be my ready recommendation. That said, if you’re looking for more finesse than this workhorses, be sure to check out Fostex’s new flagship TR Series headphones.