STAX has this week announced the SR-X9000, its latest flagship earspeakers and the first model to feature a new four-layer fixed electrode, the “MLER-3” (Multi-Layer-Elect-Rords), marking a new pinnacle; the introduction of a new generation of the metal-mesh electrode, first introduced on the SR-X in 1970.
The Japanese audio manufacturer has spent five decades researching and developing metal-mesh as the ideal material of fixed electrodes as metal-mesh reduces air resistance and the effect of reflection, allowing for high sound permeability characteristics. However, the STAX team has faced the difficulty of manufacturing metal mesh, installing and fixing it as an electrode plate over the years.
In the 1990s, the original SR-Ω was developed to increase the size of the metal mesh; however, the manufacturing technique was at its infancy as it was unpractical to produce stable products. As a result, only a few pairs of SR-Ω were made.
According to STAX, they have advanced the diffused junction (thermocompression bonding) technology that they acquired when developing the SR-009 and the SR-009s and combine the metal mesh design inherited from SR-Ω to create the “MLER-3” through a manufacturing technique resulting from 20 years of accumulated research and development. The newly developed manufacturing technique allows a rigid structure resistant to resonation while smoothly evolving the transmission characteristics of sound compared to conventional multilayer fixed electrodes.
The “MLER-3” can be mass-produced and exhibits the characteristics of high rigidity, high sound permeability and ultra-smooth sound transmission.
The diaphragm of the SR-X9000 is The SR-X9000 diaphragm is made of ultra-thin engineering film that is 20% larger than the previous flagship, the SR-009S. In addition, the diaphragm mass has been reduced to create a lightning-fast reaction speed, and high-frequency response range that seeks elevates headphone listening to a whole new level through the improvement of linearity and a more expansive sound field.
In prior offerings, the guard mesh was positioned parallel to the sound element, which generated direct reflections that did not provide any positive contribution. The guard mesh for the SR-X9000 has pillars of different lengths, ensuring that the guard mesh will not be parallel to the sound element to control the reflection angle to allow the sound waves to flow smoothly without direct reflections.

The sound unit is encased in tough machined aluminium housing with a new design adopted to firmly secure the sound unit, eliminating unnecessary resonance of the housing itself. Stainless steel is used for the arc assembly allowing it to be more tolerant to torsion and the earspeakers to fit more stably over one’s ears. In addition, an “I” type aluminium stabiliser is installed on the top of the arc to suppress the arc’s resonance and reduce the feedback of unnecessary vibration to the sound units. The arc assembly can be adjusted via a 9-step clicking slider system with the head pad featuring genuine leather on the side that comes into direct contact with the head. Similarly, genuine sheepskin leather is used for the ear pads on areas in direct contact with the skin; faux leather is used otherwise.
Two replaceable cables are bundled with the SR-X9000, one measuring 1.5 m and the other 2.5 m. Both cables sport a hybrid structure of 6NCu ultra-pure annealed copper wire (φ0.14×3) with silver-plated annealed copper wire (φ0.08×9) placed on the outer circumference of the cable and adopts the company’s wide-format 6-core parallel cable structure that reduces line capacitance.
The storage case for the SR-X9000 is made of “paulownia wood”, which has low thermal conductivity and humidity control capacity, remarked as the best storage solution by STAX.
The STAX SR-X9000 is expected to be available in October, retailing at GBP 5,395 / SGD 8,999 / USD 6,200.