Ultra-thin diaphragm with four-layer electrodes

The STAX SR-X9000 combines MLER-3 four-layer fixed electrodes, an ultra-thin diaphragm, and machined aluminum housings in an open-back electrostatic headphone. Its diaphragm has 20% more surface area than the SR-009S, supporting a spacious presentation with fast transient response. A stainless steel headband, leather contact surfaces, and two interchangeable cables accommodate extended listening.

Four layers for greater electrode stability

The SR-X9000’s MLER-3 fixed electrodes combine metal mesh and etched electrodes in a four-layer structure joined through thermal diffusion bonding. Metal mesh allows sound to pass through with less air resistance and reflection, while the bonded structure provides the rigidity needed to control resonance. This construction builds on STAX’s decades of research into mesh electrodes.

A larger diaphragm with very little moving mass

Made from ultra-thin engineering plastic film, the diaphragm responds quickly to changes in the audio signal. Its surface area is 20% larger than that of the SR-009S, helping create a broad soundstage. The low moving mass supports responsive transients and linear reproduction across the frequency range.

Machined aluminum to control vibration

The aluminum enclosure holds the sound unit securely and reduces unwanted vibration. Its internal acoustic design also limits the influence of reflected sound, helping preserve clarity as sound travels from the driver to your ears.

A stable fit with nine-step adjustment

The stainless steel headband assembly resists twisting and helps maintain a stable fit. A genuine leather head pad rests against your head, while a nine-step slider lets you adjust and retain your preferred position.

Soft sheepskin where the pads meet your skin

The ear pads use genuine sheepskin on their contact surfaces, with artificial leather around the surrounding portions. The soft, breathable contact material supports a close fit and comfort during longer listening sessions.

Two detachable cables for different listening distances

The included cables combine a 6N high-purity copper core with silver-plated annealed copper conductors. Choose the 4.9 ft (1.5 m) cable for a nearby amplifier or the 8.2 ft (2.5 m) cable when you need more reach. Both use a parallel six-strand, low-capacitance construction.

Paulownia wood storage case

A paulownia wood case provides a dedicated place to store the SR-X9000 between listening sessions. The wood’s low thermal conductivity and moisture-regulating properties make it well suited to headphone storage.

Product highlights

• Open-back, push-pull electrostatic design
  
• MLER-3 four-layer fixed electrodes
  
• Ultra-thin diaphragm with 20% more surface area than the SR-009S
  
• Machined aluminum sound-unit enclosures
  
• Angled guard mesh to manage reflections
  
• Stainless steel headband with nine-step adjustment
  
• Genuine sheepskin ear pad contact surfaces
  
• Two detachable cables included
  
• Paulownia wood storage case

Specs

• Type: Push-pull electrostatic headphones with open-air enclosure
  
• Sound element shape: Large circular
  
• Fixed electrodes: MLER-3 multilayer electrodes
  
• Frequency response: 5–42,000 Hz
  
• Electrostatic capacitance: 110 pF
  
• Impedance: 145 kΩ
  
• Sound pressure sensitivity: 100 dB
  
• Bias voltage: 580 V DC
  
• Cable conductors: 6N (99.9999%) OFC and silver-plated annealed copper
  
• Cable construction: Parallel six-strand, low-capacitance wide cable
  
• Cable lengths: 8.2 ft (2.5 m) and 4.9 ft (1.5 m)
  
• Ear pads: Genuine sheepskin contact surfaces with artificial leather surrounding portions
  
• Weight: 15.2 oz (432 g), headphones only

What’s included

• STAX SR-X9000 electrostatic headphones
  
• 8.2 ft (2.5 m) detachable cable
  
• 4.9 ft (1.5 m) detachable cable
  
• Paulownia wood storage case