S4

About the S4

The Quad S-4 is a 3-way floorstanding passive loudspeaker in Quad's S Series, featuring a bespoke 45x12mm true ribbon tweeter, a 100mm woven Kevlar midrange driver, and dual 125mm woven Kevlar bass drivers in a cabinet using MDF and high-density particleboard sandwich construction with rounded edges to reduce resonance and diffraction. It employs a rear-mounted ABR system with three 125mm passive radiators instead of a reflex port to extend bass response while maintaining articulation and control. The S-4 delivers spacious, three-dimensional sound with extended high frequencies and detailed, natural midrange and bass. Available in black or sapele mahogany wood veneers, with piano black and piano white in some markets. Recommended amplifier power is approximately 40–200W with 6Ω nominal impedance and 88dB sensitivity.