Having worked (and played) in various recording studios since the mid-’80s, I’ve seen (and worn) my share of Fostex headphones. Along with AKG K240 and Sony MDR series models, Fostex cans were everywhere in the ‘80s and ‘90s. I remember two basic versions from back in the day. There was the inexpensive T10 model, which didn’t necessarily sound great; but it was durable, comfortable, and loud. The T20 was nicer — more comfortable, better sounding, and with more isolation to avoid spill into a vocal mic — kind of a treat.
Fostex has never stopped refining its studio headphones, and the RP series (RP stands for Regular Phase, referring to the proprietary diaphragm design) has been running with the ball admirably for four decades now. With a replaceable, lockable cable system, the latest RPmk3 variants win my praise for actually being user-serviceable, while many other brands of headphones have to be sent in for repair, or often are just trashed out of convenience. The RPmk3’s newly-redesigned earcups are super-comfortable — I would actually use the word “luxurious.” At least for my head and ears, there was just the right amount of cushioning and snugness. These would be easy to wear for an all-day session.
Sound-wise, the new RPmk3 cans, at 50 Ω impedance, are capable of significant volume (helpful for drummers struggling to hear a click track, for example). I auditioned two of the three RPmk3 models — the T40RPmk3, which has closed-back earcups that provide significant isolation, and the T50RPmk3, which is a classic semi-open design. To me, both sounded quite good, although perhaps a bit dark — which can translate to “non-fatiguing” of course. The T50RPmk3 seemed a bit more natural sounding, while the T40RPmk3 provided a nice bass thump — perhaps the best bet for a drummer or bassist.
I was glad to check out these new twists on old classics and could see picking up a few pairs for my studio. Because of the slightly colored sound of the Fostex RPmk3 series, I prefer other headphones for mixing reference. On the other hand, for comfortable and efficient studio tracking — and for headphones I won’t need to repair a few times a year — my new go-to will be the Fostex T40RPmk3 and T50RPmk3.