Fostex TH1000RPmk2 is Fostex's flagship closed-back planar headphone — the closed counterpart to the TH1100RPmk2, sharing the identical RP mk2 driver, solid Japanese maple housing dyed with Awa Aizome, and magnesium alloy mechanical components. The difference between the two models is acoustic: the TH1000RPmk2 uses a closed chamber lined internally with absorbing material, resulting in higher sensitivity (100 dB/mW versus 96 dB/mW in the TH1100RPmk2), a stronger bass foundation, and passive environmental isolation. The mk2 driver with air damping control, dual-layer earpads with sheepskin and silk protein leather — identical in specification to the open-back version. Hand-assembled unit by unit, manufactured in Japan.
Closed acoustic chamber and higher sensitivity: same diaphragm, different operating conditions
The RP mk2 driver in the TH1000RPmk2 is identical to the unit in the TH1100RPmk2 — the largest RP diaphragm in Fostex headphone history with full surface drive (fully driven), a magnetic circuit using an increased number of sandwiching magnets, a newly designed printed coil pattern, and redesigned magnetic flux distribution. The closed acoustic chamber changes the operating conditions of the diaphragm relative to the open-back model: acoustic pressure builds on the internal side of the earcup, which — combined with the correct geometry and internally applied absorbing material — translates into a higher output level (100 dB/mW sensitivity), a stronger bass emphasis, and effective passive isolation from environmental noise without active noise cancellation. The internal chamber surfaces are lined with absorbing material to minimize internal reflections and resonances. Frequency response: 5–40,000 Hz, impedance: 32 Ω, maximum input: 3,000 mW.
Awa Aizome housing, magnesium alloy and mk2 earpads with sheepskin leather
The solid Japanese maple housing is dyed with Hon-ai — plant-based natural indigo from Tokushima Prefecture, the same dye used by Hokusai in the Thirty-six Views of Mount Fuji woodblock series. Dyeing is carried out by hand over several days with curing intervals; variation in temperature and humidity causes each unit to be unique in the depth and distribution of indigo color across the maple grain. Dense Japanese maple introduces no tonal coloration of its own — delivering firm, deep bass and clear, resonant treble. Mechanical components including the housing base plate and yoke are machined from magnesium alloy, reducing overall weight by 20% compared to the aluminium used in the previous generation. Weight: approx. 420 g. Mk2 earpads: dual-layer foam with silk protein synthetic leather covered by natural sheepskin leather — identical in specification to the TH1100RPmk2 but adapted to the geometry of the closed chamber. Included cable: 2 m Y-type, 7N OFC, 6.3mm plug with rhodium-plated contacts on a gold-plated base. Optional balanced cables: XLR ET-H3.0N7BL and 4.4mm ET-TH4.4BL. Leather carrying pouch included.
KEY FEATURES
- Closed-back planar design — Fostex flagship RP headphone, closed counterpart to TH1100RPmk2
- RP mk2 driver: largest fully driven planar diaphragm in Fostex headphone history, Regular Phase technology since 1974
- Mk2 optimization: air damping control inside driver + revised damping materials + new earpads for optimized diaphragm amplitude
- Closed chamber lined with absorbing material — higher sensitivity, stronger bass, passive environmental isolation
- Housing: solid Japanese maple dyed with Awa Aizome (Hon-ai, plant-based natural indigo, Tokushima) — hand-dyed over several days, each unit unique
- Mechanical components: magnesium alloy — 20% weight reduction vs. aluminium
- Mk2 earpads: dual-layer foam + silk protein synthetic leather + natural sheepskin leather
- Included cable: 2 m Y-type, 7N OFC, 6.3mm plug, detachable 2-pin rhodium-plated connector
- Optional balanced cables: XLR ET-H3.0N7BL, 4.4mm ET-TH4.4BL
- Hand-assembled unit by unit, manufactured in Japan
TECHNICAL SPECIFICATIONS
- Type: closed-back, over-ear, planar magnetic
- Driver: RP planar magnetic (fully driven, Regular Phase), largest RP diaphragm in Fostex history
- Frequency response: 5 Hz – 40,000 Hz
- Impedance: 32 Ω
- Sensitivity: 100 dB/mW
- Maximum input power: 3,000 mW
- Weight: approx. 420 g (without cable)
- Housing: solid Japanese maple + Awa Aizome (Hon-ai), closed with internal absorbing material lining
- Mechanical components: magnesium alloy
- Earpads: dual-layer foam + silk protein synthetic leather + natural sheepskin leather
- Included cable: 2 m Y-type, 7N OFC, 6.3mm plug
- Cable connector: 2-pin, rhodium-plated on gold-plated base
- Optional balanced cables: XLR ET-H3.0N7BL, 4.4mm ET-TH4.4BL
- Accessories: leather carrying pouch
- Manufacturing: hand-assembled in Japan




