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We Love to Listen
Stax SR009
Stax SR009
Stax SR009
Stax SR009


SR-009 Electrostatic Earspeakers

If a technology is not suitable for music, you should not adopt it even if it is a high-tech. Every technology should contribute to music reproduction. The SR-009 is the product of the repeated ...

Brand: Stax
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If a technology is not suitable for music, you should not adopt it even if it is a high-tech. Every technology should contribute to music reproduction. The SR-009 is the product of the repeated research trip to technology and material search without deviating from our stance to return to live sound and music always with refined sensitivity.

  • 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)
  • Specifications and appearance are subject to change for improvement.


It will exactly be as a result of "work" each predecessor piled up, if a race, a company, and an individual have "pride". And it clearly depends on the way of life we live now to inherit it and to bear "enhancement" and "evolution." Simply this is proven by the fact that the state-of-the-art technologies in the world exist intensively in present-day Japan . Making valuable new things full of creativity by skillfully taking advantage of these technologies has given birth to a "millennium" earspeaker (electrostatic headphone).


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.

ARC (head band):
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.


For those that love listening to their music in the comfort of their own home then the Stax range of electrostatic headphones, or earspeakers as they are known, will make a lot of sense. These high end audio earspeakers need an energiser unit to drive them meaning they wouldn’t be your choice if portability is high up on your feature list. Where the Stax earspeakers excel is with the clarity of sound that they’re able to produce. Stax are at the top of the headphone market in terms of the sound that is possible from headphones.

One of the first things that will strike you about the Stax earspeakers is their openness and musicality. This is the difference between dynamic and electrostatic headphones. The reasons for this are that the electrostatic drivers are much larger than dynamic drivers and due to the technology, are quicker to respond. What this actually means is that you’ll be treated to a very musical audio experience with high levels of acoustic detail.

Find out more about the Stax earspeakers by clicking on the products below, or get in touch with our team on 01865 790 879.