New flagship earspeakers equipped with newly fixed electrode MLER-3 technology.


SR-X9000 is the new flagship Earspeaker that marks the pinnacle of Stax electrostatic headphones production. A major technology advancement is the “MILER-3” (Multi-Layer-Elect-Rords) - a four-layer fixed electrode combining mesh electrodes and conventional etching electrodes that are crimped by thermal diffusion bonding. The newly developed manufacturing technique matures through a 20-year accumulated research and development, allowing a rigid structure that is resistant to resonation while smoothly evolving the transmission characteristics of sound compared to conventional multilayer fixed electrodes.

A product development story: the circular metal mesh once mounted on the SR-X was one of the ideal electrodes to reduce the effects of air resistance and reflections and increase sound permeability. However, there was a big hurdle in installing metal mesh electrodes in products because they lack strength and are resonant-prone that causes playback sound to become muddy. In the 1990s, the original SR-Ω was developed with the goal of increasing the size of the metal mesh; however, the manufacturing technique was at its infancy as it was unpractical to produce stable products. As a matter of fact, there was only a few pairs of SR-Ω were made.

The SR-X9000 diaphragm is made of ultra-thin engineering film that is 20% larger than the previous flagship SR-009S. The diaphragm mass has been reduced to create a lightning-fast reaction speed and high-frequency response range that elevates headphone listening to a whole new level.


● Type: push-pull electrostatic sound element, open-air type enclosure

● Sound element shape: large round shape 

● Fixed electrode: MLER-3 (Multi Layer Electrodes)

● Frequency response: 5 - 42,000Hz

● Electrostatic capacitance: 110pF  

● Impedance: 145kΩ  

● Sound pressure sensitivity: 100dB 

● Bias voltage: 580V DC

● Attached cable conductor: 6N(99.9999%)OFC + silver plated annealed copper wire ●Cable: parallel 6-strand, low-capacity wide cable

● Cable length:2.5m,1.5m

● Ear pad: genuine sheep leather (skin touching portion), artificial leather (surrounding portion)

● Weight: 432g (ear speaker)