Stax SR-009S Electrostatic Earspeaker


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Open-Back Electrostatic Headphones

With improved bass response and a tamed treble peak relative to the original SR-009, the SR-009S is STAX's latest effort to produce the world’s best headphone. With updated drivers, pads, and other housing pieces, the SR-009S is a step forward while still retaining much of the character of the original. 

Japanese manufacturer STAX have been developing headphones since 1938 and electrostatic headphones since 1959. Utilising electrostatic technology in their ‘earspeakers’ that are widely regarded as the best headphones available today, STAX electrostatic earspeakers are widely used throughout the world by discerning audiophiles, professional musicians, and recording companies to enjoy and monitor sound thanks to the superb sonic quality that they offer.

An electrostatic transducer is a speaker design that employs a high polymer film of several microns thick as the diaphragm for far less mass than paper or mylar cones or metal type diaphragms. Since electrostatic elements use no magnets, they are free from magnetic hysteresis distortion that is prominent in dynamic type headphones.

stax sr-009s headphones


A newly developed sound element has been adopted in the SR-009S. New high polymer ultra-thin film materials called the super engineering plastics are employed for the diaphragm of the sound element. Materials superior in tone quality have been selected to attain the excellent frequency characteristic from low to super-high as well as the vast dynamic range.

New electrodes named MLER (Multi Layer ElectRodes) have 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 and high transmissivity of sound waves. The entirely new electrodes have been constructed through the unification of metal plates processed with ultra-precision photo etching.

  • Type: Push-Pull Open Back Circular Electrostatic Headphone
  • Frequency Response: 5 - 42,000Hz
  • Electrostatic Capacitance: 110pF (including cable)
  • Impedance: 145k Ω (including cable, at 10kHz)
  • Sound Pressure Sensitivity: 101dB / 100V r.m.s. 1 kHz
  • Maximum Sound Pressure: 118dB / 400Hz
  • Bias Voltage: 580V DC
  • Left & Right Identification 
  • "L" and "R" indicated on the arc assembly (inside head spring)
  • Left channel cable is marked with a solid Line. Right channel is marked with a dotted Line.
  • Ear Pads: Genuine Lamb Leather (direct skin contact), high-quality synthetic leather (surrounding portion)
  • Cable: Silver-coated 6N (99.99%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length
  • Weight: 0.4kg without cable / 0.5 with cable
Stax SR-009S electrostatic headphones

The very first thing to say is that if you haven’t heard a pair of electrostatic headphones, you are going to be blown away if you listen to a pair of SR-009S earspeakers in combination with the Stax SRM-700S. more... Stax SR-009S Electrostatic Earspeaker

The SR-009S is a masterful achievement that expands upon the SR-009’s strengths, offering heightened detail and focus, more nuanced and expansive dynamics, and superior bass. more...

Due to the bespoke nature of our high-end music systems this product is not available to be purchased online. Please contact us for personalized service from one of our team of experts.