Stax SR-009S Electrostatic Earspeakers

Overview:

Multilayer fixed electrode MLER (Multi-Layer-Elect-Rords) established with SR-009 has evolved to MLER 2. The finish and etching process that smoothes the edge of the electrode opening reduces air resistance and further improves sound permeability. Also, the electrodes themselves are gold plated with high specific gravity to minimize the resonance of the ultra-thin electrode. At the same time, due to the effect of reducing the electric resistance of the electrode itself by gold plating, we have opened up a new ground for high speed, clarity, silky details, and powerful texture.

SR-009S adopts a diaphragm made of ultra-thin super engineering plastic film. The light mass has realized a high transient characteristic throughout the entire audio spectrum.

The main body was redesigned to further reduce resonance as to provide a consistent sound.

Sound element with new fixed electrodes

If the fixed electrode becomes infinitely thinner, the air resistance will be de- creased and the permeability of sound waves will be improved. On the other hand, thinner electrodes are poor in rigidity and suffer from vibrations of their own and the sound becomes muddy.The SR-009S evolved further the electrode established in the SR-009 as the integration of present technology.

The edges of electrode hole were smoothened through after-etching processing to reduce air resistance, and the permeability of sound has been much more improved. Moreover, gold plating processing with large specific gravity further decreased the electrode vibration. Finally, the sound clarity has been achieved by reducing the resistance of electrode itself.

Tough solid aluminum chassis 

It employed secures firmly the sound element, con- tributing to improve the clearness of sound. Furthermore, the case thickness has been reduced to the limit, making the flow of condensation-and-rarefaction air wave from the sound element more smooth.

New designed guard mesh
Intensity has been increased by giving roundness to the “guard mesh” of sound element, which lowered the influence of reflection and improved the resolu- tion of sound.

Enclosure
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.

Cable
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.

Earpad
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.

SR-009S Specifications:

• 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 (99.9999%) OFC parallel 6-strand, low-capacity special wide cable, 2.5m full length
• Weight: 1lb without cable / 1.3lb with cable