REL Acoustics S/850

Effortless Power, Tuned for Musical Authority
S/850 is engineered for listeners who want uncompromising performance with a refined, musical touch. Drawing on innovations from our Reference line, it pairs an 850-watt Linear Class D amplifier with advanced CarbonAlloy™ drivers to deliver explosive dynamics, clarity, and effortless scale. Equally at home in high-end music systems or immersive theaters, S/850 brings control and confidence to medium-to-large rooms.

850-watt Linear Class D Amplifier for fast, controlled power delivery

12" CarbonAlloy™ Active Driver with 12" long-stroke Passive Radiator for depth and speed

Optimized for music and theater systems in medium-to-large rooms

Designed for stereo pairs and line-array configurations

Optional premium wood grille available. Crafted from natural materials, each grille features unique grain and color variations

Exceptional Design Meets Unmatched Power

S/850 represents the pinnacle of the Serie S series, with its engineering breakthroughs shaping and elevating its three companions. Every advancement is sweeping and extensive, ensuring the entire Serie S lineup benefits from the refinements pioneered in the S/850.

The outcomes are breathtaking: it delivers astonishing impact and output beyond even the prior Carbon Special at the outer limits of capability, yet with the accuracy, silence, and definition that produce authentic dynamic expression. Ultra-fast attacks, profound effortless bass, and tonal richness merge to create detail that enhances both music and cinema.

This model redefines what a reference subwoofer can accomplish, offering both explosive energy and graceful nuance. Audiophiles and home cinema enthusiasts alike will recognize the extraordinary balance between raw power and refined articulation.

Crafted for Precision

The S/850 cabinet is elongated, lowered, expanded, and deepened—proportions that grant it a naturally authoritative presence. Subtle stylistic refinements polish its appearance and texture: clean lines that reflect light, warm silver-gold insignia with a titanium-like surface, and steel handles inset into smooth ellipses. Beneath each forward rail, meticulously milled billet cylinders enable precise leveling, while thick interior aluminum slabs secure the grips for secure stacking in Line Arrays. Created to complement contemporary interiors, the S/850 also includes an optional Premium Wood Grille, adding warmth and individuality.

By blending aesthetic appeal with functional integrity, the design becomes both visually pleasing and acoustically optimized. The integration of premium materials ensures both longevity and unmatched resonance control.

Engineered for Ultimate Performance

The S/850 is the culmination of relentless optimization. This progress stems not only from exploring newer, finer resources, but also from the thousands of hours of critical evaluation our team completes each season—experience that transforms pure design into musical and cinematic delivery of the highest caliber. With each element carefully evaluated, the S/850 delivers a scale, nuance, and power that surpasses what was previously possible in its category.

S/850 transducers now showcase lightweight pure carbon-fiber central caps, replacing the solid aluminum moldings of prior units. These caps decrease moving mass while stiffening the diaphragm, producing explosive dynamics and the ability to reveal the faintest moments with finesse and delicacy. Ultra-light yet rigid, they extend performance at both limits—a trademark of REL innovation.

This fusion of reduced weight and strengthened rigidity provides unmatched clarity across the frequency range. It is a sophisticated synthesis of materials engineering and acoustic artistry.

Monoblock Power with Class D Efficiency

The S/850’s amplifier delivers the punch of enormous Class A/B monoblocks while exploiting the economy of a contemporary Class D output module. Backed by a sturdy conventional power supply, it generates 850 watts of sustained output and can peak at 1,000 watts during intense demands, ensuring vast overhead for both music and cinema. Enhanced input filters, equipped with the same thin-film capacitors used in REL’s flagship designs, introduce a heightened level of definition and refinement never before offered in this segment. Together, these upgrades create profound improvements in transparency, staging, and overall authority—an amplifier that blends brute impact with subtlety to anchor the character of the entire Serie S family.

Listeners benefit from increased speed and dynamic headroom without sacrificing tonal smoothness. This amplifier exemplifies the union of cutting-edge efficiency with uncompromising sonic power.

Analog Filtering at Its Finest

We select analog because it is the only approach to achieve genuinely organic sound. All REL input circuits are 100% analog—among the quickest ever built into a subwoofer. At the heart is our acclaimed High Level Input, which attaches directly to the loudspeaker outputs of your primary amplifier. This doesn’t consume power; instead, it conveys the full tonal imprint of your system, allowing REL to integrate flawlessly with your loudspeakers—a capability critics have commended for decades.

For setups where High Level isn’t viable, our low-level connection uses the identical analog filter design, available through both RCA and XLR jacks, to deliver the immediacy, authenticity, and integration REL is celebrated for. And in cinema or dual-purpose systems, REL uniquely enables High Level and .1/LFE to operate together—so music benefits from seamless integration, while movies achieve the complete intensity intended by the soundtrack.

This fusion of flexibility and sonic purity ensures compatibility across a wide variety of systems. The analog approach guarantees natural timing and realism that digital solutions simply cannot replicate.

Serie S Line Array Integration

REL Line Arrays are revered for their expansive staging and scale—performance that continues to lead the premium audio industry. Like every REL Line Array, they’re built to expand with the listener: begin with a stereo pair, advance to four, and ultimately stack six units for commanding floor-to-ceiling authority. Precision mechanical couplers fasten each upper unit firmly to the base REL beneath, ensuring both rigidity and seamless coherence.

The S/550 functions as the entry point into this universe, providing a scalable path into Line Array capability. Advancing to the S/850 brings enhanced scale, weight, and authority—proven globally at exhibitions to elevate meticulously matched systems. The outcome is transformative: vocals gain remarkable immediacy, instruments expand with natural body, and cinematic events erupt with realism. A genuine cutting-edge encounter, designed to be scalable and accessible.

The modularity ensures longevity, as systems can expand over time without losing coherence. This adaptability underscores REL’s dedication to future-proof high-end system architecture.

Advanced Wireless Signal Transmission

At times the best cable is no cable. Premium wires are a standard in elite audio installations, but there are circumstances where it is impractical, unsafe, or visually disruptive to stretch a wire across a space. REL supplies the superior answer with Airship Direct™, our optional wireless platform that transmits wide-bandwidth, compound signals, carrying both High Level and .1/LFE concurrently. Even with the immense scale and capacity of S/850, Airship Direct™ preserves the immediacy, precision, and authority that characterize REL. It permits fluid changes between audio and video without adjusting any controls, all from a compact module that plugs directly into the rear panel and remains discreet in your room. Simple, precise, uncompromised: Airship Direct™.

This technology eliminates installation challenges while retaining uncompromised fidelity. It offers convenience without sacrificing the integrity of professional-grade audio transmission.

Specifications

Physical characteristics