Fostex T50RP Mk4 EQ settings
Filled in the presence of the popular planar mod platform. These parametric EQ settings correct the Fostex T50RP Mk4's measured frequency response toward a neutral target. The closed-back wired headphone keeps its strengths; the EQ fixes the rest.
How the T50RP Mk4 sounds before EQ
Measured against a neutral target, the T50RP Mk4 comes out near-neutral. It already tracks the target closely, so the correction is polish rather than surgery.
The presence region, vocal clarity and attack, sits about 4.4 dB behind neutral, so detail and clarity soften. The sub-bass region, rumble and the weight under kick drums, sits about 3.3 dB behind neutral, so kick drums lose their weight. The lower mids region, warmth and the body of voices, sits about 1.8 dB forward of neutral, so voices and guitars thicken up. The treble region, cymbals, sibilance and sparkle, sits about 1.3 dB forward of neutral, so cymbals and s-sounds can sting.
The largest deviation runs to about 4.4 dB, which is impossible to miss. This model benefits clearly from correction.
These figures are read from the correction itself: whatever the EQ lifts, the headphone lacked, and whatever it cuts, the headphone had too much of. The target is the community's neutral reference, and how far above 10 kHz you can trust any measurement varies by rig. More near-neutral models.
The correction curve
The solid line is the full measured correction (all 10 filters). The dashed line is what Atrium applies: the same shape at 65 percent strength, capped at 6 dB per band, so the headphone keeps its own character instead of being forced flat.
What the EQ fixes
The biggest moves in this correction, and what they do:
- The filter at 3.95 kHz lifts the clarity region by 6.6 dB with a medium-width band (Q 1.06).
- The filter at 1.05 kHz cuts the vocal presence region by 6.2 dB with a broad band (Q 0.78).
- The filter at 6.96 kHz cuts the treble by 5.5 dB with a medium-width band (Q 1.52).
The preamp of -6.3 dB offsets the boosts so nothing clips at full volume.
Parametric EQ settings
Preamp: -6.3 dB (prevents clipping from the boosts below)
| # | Type | Frequency | Gain | Q |
|---|---|---|---|---|
| 1 | Low shelf | 105 Hz | +2.7 dB | 0.70 |
| 2 | Peaking | 3.95 kHz | +6.6 dB | 1.06 |
| 3 | Peaking | 1.05 kHz | -6.2 dB | 0.78 |
| 4 | Peaking | 2.15 kHz | +3.7 dB | 1.00 |
| 5 | Peaking | 6.96 kHz | -5.5 dB | 1.52 |
| 6 | High shelf | 1 kHz | +1.3 dB | 0.70 |
| 7 | Peaking | 57 Hz | -2.1 dB | 0.43 |
| 8 | Peaking | 392 Hz | +1.2 dB | 1.27 |
| 9 | Peaking | 585 Hz | -1.7 dB | 4.58 |
| 10 | Peaking | 21 Hz | +4.4 dB | 1.07 |
This is the full measured correction in AutoEq format. It pastes straight into Equalizer APO or Peace on Windows, and into most parametric EQ apps.
How to use these settings
Manually: enter the preamp and each filter into any parametric EQ. On Windows that is usually Equalizer APO with the Peace interface. On a Mac, eqMac or SoundSource. Set the type, frequency, gain and Q exactly as listed.
With Atrium: pick your T50RP Mk4 in the app and it applies a tuned version of this correction: 65 percent strength with a 6 dB per-band cap, which fixes the rough spots without erasing what the headphone does well. Atrium also measures how you hear with a short listening test and layers your personal hearing profile on top. Two people with the same headphones do not hear the same sound. Headphone corrections are part of Signature Edition; the app itself is free.
T50RP Mk4 vs other Fostex models
Bass and treble are each model's average distance from the neutral target in that range. Positive means more than neutral, negative means less.
| Model | Signature | Bass vs neutral | Treble vs neutral |
|---|---|---|---|
| T50RP Mk4 (this page) | near-neutral | -1.6 dB | -1.5 dB |
| T-X0 | near-neutral | -1.8 dB | -1.9 dB |
| T20RP Mk3 | near-neutral | -1.0 dB | -1.0 dB |
| T40RP Mk3 | warm | +1.1 dB | -1.9 dB |
| T50 | bass-light | -4.8 dB | -2.5 dB |
Headphones that sound similar
Closest matches across all 4,332 measured models, by distance between their deviation curves. Useful if you like how the T50RP Mk4 is tuned and want alternatives.