REL Acoustics Ltd S/850 Subwoofer

Performance, elegance and absolute control

The REL S/850 is the most powerful model in the S series and has been meticulously designed to deliver maximum bass quality in demanding stereo and home theater systems. Its wider yet shallower cabinet gives it a powerful visual presence, while precisely crafted details such as recessed stainless steel handles, finely knurled aluminum cylinders, and the signature emblem underscore the series' high-quality workmanship. The subwoofer can also be optionally fitted with a wooden grille, which optimizes both aesthetics and airflow.

Powerful drive and precise membrane technology

At the heart of the S/850 is a newly developed 12-inch CarbonAlloy active driver. The combination of an exceptionally lightweight carbon fiber core and a reinforced alloy creates an exceptionally rigid, low-resonance diaphragm. This allows the subwoofer to achieve an impressive blend of speed, dynamics, and accuracy. The system is complemented by a downward-firing 12-inch passive radiator, which provides additional depth and impact. The combination of active driver and passive radiator creates a bass foundation that is impressively present in both music and movies.

Powerful amplifier

The integrated linear Class D amplifier delivers 850 watts of continuous power, providing enormous energy reserves. Its architecture combines the powerful transient response of classic Class A/B monoblocks with the high efficiency of modern Class D technology. This design allows for confident control of the large driver, even at high volume levels. Therefore, the S/850 is ideally suited for larger living rooms or setups that demand powerful yet musically balanced bass reproduction.

Analog filter architecture for maximum naturalness

REL traditionally relies on fully analog filters for its S series. The S/850 follows this philosophy as well: High-level inputs allow direct connection to the main amplifier's speaker outputs, ensuring the subwoofer precisely replicates the system's sonic signature. For setups without a high-level option, low-level inputs are available via RCA or XLR. The ability to operate high-level and .1/LFE simultaneously is particularly useful – a benefit for users who want to use a subwoofer for both music and movies.

Optimized for line arrays

The S/850 was designed from the outset for use in line arrays. Multiple subwoofers can be stacked vertically and precisely connected, allowing them to function as a single, large bass source. Newly developed aluminum adjustment knobs integrated into the cabinet rails facilitate precise alignment – even on carpet or softer floors. This enables effective and stable installation of setups with two, four, or six S/850s. This technique delivers exceptionally deep, even, and room-filling bass projection.

Wireless use

For situations where cables are undesirable, the S/850 is compatible with the optional AirShip Direct wireless module. This transmits high-level and .1/LFE signals across the full bandwidth, allowing for flexible placement without any significant sonic drawbacks. This makes it possible to integrate the subwoofer discreetly into almost any living space.

Technical data

• Type: Active front driver, passive down-firing radiator
• Active driver: 12" (305 mm) CarbonAlloy cone, die-cast aluminum chassis
• Passive radiator: 12' (305 mm) carbon/carbon flat cone, steel chassis
• Low-frequency extension: -6 dB at 19 Hz
• Inputs: High-Level Neutrik Speakon, 2 × RCA Low Level, 1 × LFE RCA, 1 × LFE XLR
• Outputs: High-Level Speakon, 1 × RCA, 1 × LFE RCA or XLR
• Amplifier power: 850 W RMS
• Amplifier type: Linear Class D
• Wireless Function: Compatible with AirShip Direct™ (optional)
• Case finish: Piano Black or Gloss White, 8-layer lacquer
• Protection systems: Set-Safe, DC fault, short circuit
• Mains voltage: 220–240 V or 110–120 V per store
• Fuses: 8 A (220 V), 15 A (120 V)
• Dimensions (W × H × D): 488 mm × 410 mm × 540 mm
• Weight: 42.5 kg