STAX SR-009 Open-Back Electrostatic Headphones

The newly developed sound element has been adopted in the SR-009. New high polymer ultra-thin film material called the super engineering plastics – the reinforced material of the conventional engineering plastics – is employed for the diaphragm of the sound element. Materials superior especially in tone quality have been selected to attain the extremely excellent frequency characteristic from low to super-high as well as the vast dynamic range.

New electrodes named MLER (Multi Layer ElectRodes) have also been developed to realize the plane drive of the whole film diaphragm surface. While infinite thinness and flatness are required for the fixed electrodes, they simultaneously need to have other characteristics such as low resonance, high transmissivity of sound wave, and so on. The entirely new electrodes have been completed through the unification of metal plates processed with ultra-precision photograph etching using the high technology of heat diffusion combination on the atomic level.

Aluminum is a metal good for sound and suitable material for audio equipment. It is abundantly used, e.g. at the frame supporting the appearance and sound element, to realize high-quality sound, rigidity and lightweight. Almost every part of the SR-009 is manufactured through precise machine processing.

The high-purity copper developed from the necessity of wiring large-scale integration circuits is also known as high-quality audio cables. High-purity copper wire of 99.9999% (6Nines) purity adopted for the cable is further silver-coated and finished with the most suitable structure to drive the earspeaker.

The earpad of a new design is carefully made by a craftsman’s hand and features both the real leather with good humidity environment and the cushion material with moderate elasticity.

The new earpad enables hours of comfortable listening to music.

The arc is equipped with a position adjustment mechanism of 10-step slider and corresponds to the wide range of cranial form with individual difference.

● Type: push-pull electrostatic circular sound element, open-air type enclosure
● Frequency response: 5 – 42,000Hz
● Electrostatic capacitance: 110pF (including cable)
● Impedance: 145kΩ (including cable, at 10kHz)
● Sound pressure sensitivity: 101dB / input 100Vr.m.s. / 1kHz
● Maximum sound pressure level: 118dB / 400Hz
● Bias voltage: 580V DC
● Right/left channel indication: ’L’ and ‘R’ indicated on the arc assembly (inside head spring), solid line (left) and dotted line (right) on the cable
● Earpad: real leather (skin touching portion), high-quality artificial leather (surrounding portion)
● Cable: silver-coated 6N (99.9999%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length
● Weight: 596g (including cable), 454g (without cable)