Fostex TH-1100RP-MK2 – TH Premium Series Open-Back Headphones With RP Drivers, Indigo Blue

The flagship RP "mk2" has further evolved its unparalleled high-resolution sound by refining the outstanding reproduction capability of the premium flat-plane diaphragm RP driver.

This product is the mk2 version of our flagship RP headphones, carefully assembled one by one at our factory in Japan using Fostex's proprietary premium grade RP driver with a fully-driven planar diaphragm, optimized diaphragm movement centered on air damping control inside the driver, and a connector that is easy to re-cable. The mk2 flagship RP headphones are carefully assembled one by one at a factory in Japan. The beautiful indigo color and texture of the wood grain of the housing, hand-dyed by skilled Awa Indigo craftsmen, combined with the overwhelming resolution and faithful expression of the premium RP drivers, provide an exquisite audio experience in which traditional craftsmanship and acoustic technology coexist.

*RP and RP technology are Fostex's proprietary technologies that move the entire surface of the flat diaphragm in regular phase (Regular Phase).

Premium RP Driver mk2 with optimized diaphragm movement through air damping control

The Premium RP Driver, developed using the largest diaphragm ever used in a fully driven planar diaphragm driver based on RP technology that has been refined since 1974, has been further optimized with mk2 technology through air damping control inside the driver, flow ad-justment using damping materials and new ear pads. This achieves ideal diaphragm amplitude, particularly in the low-frequency range. The Premium RP Driver’s large diaphragm and mag-netic circuit suppress unwanted resonance, delivering sharp response, high sensitivity, smooth frequency characteristics, and excellent transient response. Additionally, the mk2 version achieves the ability to faithfully and clearly reproduce sound images from the low-frequency range to the high-frequency range in space with precise localization.

Newly adopted mk2 ear pads with a new shape and two-layer internal structure

The newly adopted ear pads in the mk2 feature a sloped design on the side that contacts the face, optimizing comfort. The internal low-density urethane foam is arranged in a two-layer structure, with a soft type on the outer side and a high-elasticity type on the inner side to con-form to the shape of the face. Additionally, the adoption of silk protein-based synthetic leather, which offers three times the durability of the previous model, ensures comfortable wear even during extended listening sessions.

Features a 2-pole 3.5 mm connector and comes with a high-purity OFC unbalanced Y cable

The mk2 version uses a 2-pole 3.5 mm connector, improving re-cable compatibility and versatil-ity. The internal wiring and included unbalanced cable utilize 7N (99.99999%) grade high-purity OFC (Oxygen-Free Copper) cable, which minimizes impurities to maximize transmission per-formance. Additionally, a separate 4.4 mm balanced cable (ET-TH4.4BL2Y) is available for purchase.

Hard maple solid wood housing finished with Awa Aizome, a traditional Japanese dye developed in collaboration with local artisans

Awa Aizome indigo, which has long been prized for its use in high-quality dyeing, was developed in collaboration with Awa indigo artisans and used to dye the hard maple solid wood housing, which is known as a material for guitars. Each piece is meticulously dyed by skilled artisans, resulting in a deep indigo blue that beautifully highlights the unique grain of hard maple. The dyeing process using “Hon-ai,” made solely from plant-based indigo, leverages the hard maple’s dense, high-density properties that do not impart unnecessary tonal coloration, delivering a robust, deep low-frequency range and clear, resonant high-frequency range. The open-type TH1100RPmk2 features double-layered aluminum etched parts at the housing opening, with meticulous fine-tuning of the opening ratio and internal components. This design reproduces a natural soundstage with high resolution and minimal listening fatigue, befitting the premium quality of the open-type RP series.

About dyeing with Awa Aizome

Awa Aizome indigo, a traditional natural dye from Tokushima, has been known throughout Ja-pan since ancient times as an indispensable dye for high-quality dyed fabrics due to its beautiful color. However, it was difficult to dye wood using conventional methods, and trial and error was repeated in adjusting the dye concentration, fermentation process, and soil preparation. The housings of the TH1000RPmk2/TH1100RPmk2 are dyed using “genuine indigo” made exclu-sively from natural indigo plants, with the dyeing process involving repeated application and drying by hand over several days. During this process, changes in temperature and humidity affect the dye’s drying, and the condition of each housing’s wood grain alters the conditions under which fine pigment particles penetrate the wood’s structure. This results in a housing that combines the deep blue unique to Hon-ai with the smooth grain of maple wood, creating a truly innovative color where each product’s texture varies from left to right.

Newly adopted lightweight magnesium alloy mechanical parts

A refreshed design using Magnesium alloy for mechanical parts, such as the housing base plate and hanger, help reduce overall weight by 20% compared to aluminum. Rubber packing is used for the rotation mechanism to eliminate excess vibration as much as possible. The design con-cept of taking every detail of each part into consideration has further improved the wearing comfort.

Flexible fitting head pad and headband

The head pad and headband are made of natural sheepskin material, providing a supple and comfortable fit.

Specifications

• Type Open-back Dynamic


• Driver RP planar magnetic


• Impedance 32 ohm


• Sensitivity 96 dB/mW


• Max Input 3,000 mW


• Freq. response 10 – 40,000 Hz


• Weight Approx.420 g (excluding cable)


• Cable Φ3.5 mm(2-pole)x2 to Φ6.3 mm(gold-plated 3-pole) 2 m unbalanced cable x 1


• Accessories Leather pouch, Safety precautions


• Attention After use, wipe sweat, sebum, hair styling products, foundation, etc. adhering to the earpads and headpads with a dry cloth.


• Ear pads are consumable items. Please replace them as needed because they deteriorate due to daily use and long-term storage.

• Type Open-back Dynamic
• Driver RP planar magnetic
• Impedance 32 ohm
• Sensitivity 96 dB/mW
• Max Input 3,000 mW
• Freq. response 10 – 40,000 Hz
• Weight Approx.420 g (excluding cable)
• Cable Φ3.5 mm(2-pole)x2 to Φ6.3 mm(gold-plated 3-pole) 2 m unbalanced cable x 1
• Accessories Leather pouch, Safety precautions
• Attention After use, wipe sweat, sebum, hair styling products, foundation, etc. adhering to the earpads and headpads with a dry cloth.
• Ear pads are consumable items. Please replace them as needed because they deteriorate due to daily use and long-term storage.