Stax SR-009
Stax SR-009
Stax SR-009

Stax SR-009: Reference class headphones

The Stax SR-009 headphone model can be called the material embodiment of the idea of ​​absolutely accurate natural sound. These electrostatic headphones were Stax’s next step towards excellence, displacing the previous hit SR-007MK2 from its pedestal.

The changes affected the electrostatic film membrane, the thickness of which is now only 2 microns and which is made of a special polymer, which is a reinforced structural plastic. The membrane is placed between two multilayer electrodes MLER (Multi Layer ElectRodes) – stators consisting of metal plates manufactured using the photochemical deposition process (photolithography) and interconnected through thermal diffusion. This design provides excellent microdynamics, and the diffuser film itself has the highest response speed. All this allows you to improve the tonal accuracy of the sound and obtain a wide frequency range.

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The round earcups of the Stax SR-009 headphones have protective grilles and are made of aluminum alloy, and are also milled on high-precision machines. The contact surface of the ear cushions, which have elastic elastic padding, is made of soft, breathable lambskin. Therefore, even after many hours of listening, the headphones do not tire. The headband consists of a main plastic arch along which sliders slide with a pad fixed between them. The slider mechanism allows you to fix them in 10 positions and thus adjust the position of the pad in accordance with the desired head size.

The cable consists of six cores connected in parallel, which helps reduce the capacitance that occurs between them. The main material is oxygen-free copper of the highest purity (99.9999%), which is coated with a thin layer of silver and covered with polyvinyl chloride insulation. The cord has a five-pin connector.


To work with Stax SR-009 headphones, it is recommended to use the top-end branded amplifier Stax SRM-T8000 , which will ideally suit them in terms of characteristics and will be able to fully reveal their potential. The sound of the headphones is neutral.

Provides an ideal stage, the highest quality of highs and mids, as well as rich and articulate bass. The model is capable of handling the most complex orchestral compositions, which once again emphasizes its highest reference class.

Characteristics of Stax SR-009

Open electrostatic headphones
Category wired
Emitter electrostatic, has a round shape
Frequency range 5 – 42000 Hz
Capacitance (including cable) 110 pF
Impedance 145 kOhm (including cable, at 10 kHz)
Sensitivity 101 dB (100 V, 1 kHz )
Maximum sound pressure level 118 dB (400 Hz)
Required (polarizing) voltage 580 V DC
Cup material aluminum alloy
Ear pad material sheep leather (contact surface), high-quality artificial leather
Cable six parallel cores, material: silver-plated oxygen-free high purity copper 6N (99.9999%)
Cable length 2.5 m
Cable plug 5-pin
Headphone case made of fine wood
Weight 596 g (with cable); 454 g (without cable)