Synergistic Research Foundation SX Headphone Cable

Key Features: 

• Handmade Air String Geometries with 99.9999% Pure Silver Conductors in Air Dielectric – Maximizes resolution, detail, and dynamic clarity for holographic, fatigue-free listening.
• UEF Matrix Shielding with Graphene – Dramatically lowers the noise floor and prevents harshness for smoother, more transparent sound.
• Long Duration High Voltage Conditioning – Enhances tonal accuracy, dimensionality, and overall musical realism for lifelike performance.
• Included UEF Carbon Tuning Discs – Allow system-specific voicing to balance musicality and resolution according to personal preference.
• Wide Range of Connector Options – Supports multiple headphone brands and models, enabling seamless integration with your existing rig.

Product Description: 

Foundation SX headphone cables are handmade in our California factory from core Synergistic Research technologies, including handmade Air String Geometries made or pure 99.9999% Pure Silver conductors in an Air Dielectric for unmatched resolution. We then add UEF Matrix Shielding with a new UEF Compound first developed for our SRX cable loom for a dramatically lower noise floor. Next we include a new Long Duration High Voltage Conditioning Process, initially engineered for our flagship SRX cables, making Foundation SX the most musical and highest resolution headphone cables you can buy. With a full suite of SR Technologies, you hear inner detail and holographic realism that’s never harsh or fatiguing, unlike most pure silver-based cables. And to make voicing them to your headphone rig easy, we include UEF Carbon Tuning discs to strike the perfect balance of musicality and resolution. In short, we’ve created the world’s best headphone cables, and we’re confident you’ll love their sound over ANY headphone cable on the market, regardless of price. So step up, take the Foundation SX Challenge and discover how good your current headphone system actually is.

UEF Matrix Shield with Graphene Matrix Shielding

The original Atmosphere X Series began as an experiment in advancing UEF Shielding by positioning UEF elements at strategic grid points along the shields—an approach that became known as Matrix Shielding. This design lowered the noise floor by arranging UEF elements in a grid pattern across the shield.

With Atmosphere SX, Matrix Shielding has been refined even further through the introduction of Carbon Fiber UEF Tuning Discs, created specifically for this series. These discs enhance the loom’s ability to cancel noise that would otherwise lead to harsh or fatiguing high frequencies. As a result, Atmosphere SX delivers greater holographic scale, improved resolution, and heightened musicality—pushing the boundaries of what UEF Shielding can achieve.

Quantum Tunneling—SRX Long Duration High Voltage Conditioning

First developed for the flagship SRX series, the new high-voltage conditioning process uses an extended sweeping frequency plot applied over long durations. During development, dozens of frequency combinations were tested before arriving at the ideal formula, and a new Tesla Coil was engineered to manage the heat generated during these extended sessions. The result is a conditioning process that delivers holographic realism and timbral accuracy well beyond what was possible with the earlier Tesla Coil protocol.

Available  Source Connections

4 PIN XLR, 3.5mm connector (with  included 6.35mm (1/4″) adapter) or Dual 3 PIN XLR (+$100)

Additional connections may be available upon request.

Destination Connections

• 2 Pin Lemo (Focal Utopia)
• 3 Pin Lemo
• MMCX ( Pioneer SR-Master1: Shure SRH1540 and SRH1840)
• Sennheiser Push-Pull (Sennheiser HD820, HD800S, and HD800)
• Sennheiser 2 Pin (Sennheiser HD650, HD600, HDXX)
• Mr.Speakers 4 Pin Hirose (MrSpeakers: Aeon, Ether 2, Ether 2 Closed, Flow, Flow closed
• 4 Pin Mini XLR (Audeze LCD4,3,2,X, XC: Meze Empyrean: ZMF Atticus, ZMF Eikon)
• 3 Pin Mini XLR
• 2.5mm Mono (Hifiman Old Styles)
• 3.5mm Mono
• 3.5mm Stereo (Hifiman current: Ananda, Susvara, HE1000, HE400i, HE500, HE6 and HE650)
• 8 Contact
• SMC
• TRRS (2.5mm and 3.5mm)

Always confirm your connections with your headphone manufacturer. Additional connections may be available upon request.

Specifications: