Fostex T50RPmk4g+ is a semi-open gaming headset built on the fourth-generation RP planar driver, adding a dedicated detachable microphone, an inline controller, and a 3.5 mm TRRS combo cable to the T50RPmk4g platform. It is the first Fostex headset to include a microphone, while retaining the full T50RPmk4 hardware base: symmetrical housing with sockets on both sides, the fourth-generation planar driver with redesigned printed coil, and increased magnet count.
Fourth-generation RP driver in a gaming context — what planar technology actually delivers
The technical advantage of the T50RPmk4g+ over dynamic-driver gaming headsets is specific: RP planar technology drives the entire diaphragm surface uniformly, minimizing phase distortion and producing fast transient response. In competitive gaming terms, this means sharper localization of brief transient signals — footsteps, gunshots, environmental cues — where the time-accuracy of the reproduced impulse directly affects in-game decision speed. At 28 Ω and 97 dB/mW sensitivity, the headset drives directly from a controller, laptop, or onboard audio without an external amplifier. The symmetrical housing — identical sockets on both left and right earcups — eliminates the internal acoustic asymmetry present in headphones where only one side carries cable routing components, resulting in more balanced channel separation and a more defined stereo image.Microphone, inline controller, and cable topology
The microphone connects to either earcup socket, accommodating both left- and right-side preferences without modification. The controller integrated into the microphone cable handles microphone mute (ON/OFF toggle) and headphone volume via a slider — a straightforward implementation with no software dependency. The included 2.0 m cable terminates in a 3.5 mm TRRS combo jack, compatible with laptops, consoles, and mobile devices with a single headset socket. Setups with separate mic and headphone 3.5 mm ports require a TRRS splitter. Memory foam circumaural ear pads provide consistent acoustic seal and stable fit during extended sessions.KEY FEATURES
- 4th-generation RP planar driver — full-surface diaphragm drive, fast transients, precise spatial localization
- Detachable microphone connecting to either earcup — flexible routing for left- and right-handed setups
- Inline controller on microphone cable — microphone mute toggle and headphone volume slider
- Symmetrical housing with bilateral sockets — balanced channel separation, no internal acoustic asymmetry
- 28 Ω impedance / 97 dB/mW sensitivity — drives without external amplifier
- Semi-open design — natural soundstage with moderate ambient isolation
- Memory foam circumaural ear pads — stable seal and comfort over long gaming sessions
TECHNICAL SPECIFICATIONS
- Model: T50RPmk4g+
- Driver type: Planar magnetic RP (Regular Phase), 4th generation
- Design: Semi-open
- Impedance: 28 Ω
- Sensitivity: 97 dB/mW
- Frequency response: 10 Hz – 40,000 Hz
- Maximum input power: 3,000 mW
- Microphone: Detachable, connects to left or right earcup
- Controller: Microphone mute + volume slider (inline on microphone cable)
- Cable: 2.0 m, 3.5 mm TRRS (combo jack)
- Weight: approx. 330 g (without cable)





