Fostex T50RPmk4CL Closed-Back Planar-Magnetic Studio Headphones

The T50RPmk4CL takes the fourth-generation RP planar driver and seals the housing. That is the version engineers have been asking Fostex for: the same 28 ohm, 97 dB/mW driver, but with the back of the cup closed so a vocalist can work against a loud cue mix without the mic hearing it. Isolation also cuts both ways on a location shoot, where the closed cup keeps room noise out of the monitoring path.

Everything else matches the semi-open mk4. Both cups take the 3.5 mm 4-pole plug so the detachable cable runs down either side, the weight stays at 330 g, and the response is quoted over the same 10 Hz to 40 kHz span. A 2 m unbalanced cable and a 3.5 mm to 6.3 mm conversion connector ship with it.