Foundation SX Headphone Cables

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.

Engineered with audiophile-grade components — premium drivers, hand-matched crossovers, and a hardwood enclosure tuned for natural decay. Every cabinet is internally braced and damped to suppress resonance below the threshold of audibility.

• Custom 6.5" mid-bass driver with paper-pulp cone for transient accuracy.
• Soft-dome silk tweeter with neodymium motor for airy, fatigue-free highs.
• Point-to-point hand-wired crossover using silver-foil capacitors.
• Bi-wirable terminals plated in pure copper.

Place each speaker on its dedicated stand, toed-in toward the listening position. The hardwood enclosure resonates in concert with the drivers — a deliberate, musical interaction rather than a flaw to be eliminated.

Connect to a quality amplifier using bi-wired speaker cable for the most transparent presentation. Allow 50–100 hours of break-in for the drivers and crossover capacitors to settle into their final voicing.