S850 Subwoofer

Serie S/850 - A Template for Greatness

The S/850 is the foundation of Serie S, the model upon which the entire range is built. Lessons first proven here shaped every other design. With an 850-watt amplifier driving a 12" CarbonAlloy™ active driver and a 12" down-firing passive radiator, its performance is nothing short of spectacular: explosive attack, immense output, and quiet refinement. With precision, quietness, and clarity, the S/850 delivers true dynamic range, effortless depth, and bass rich in tonal color and nuance. It is the benchmark of Serie S and the standard by which all others are judged.

• Optional premium wood grille available.

Driven to Perfection
The S/850 is the result of relentless refinement. This progress comes not only from exploring newer, finer materials, but also from the thousands of hours of critical listening our team undertakes each year—experience that transforms raw engineering into musical and theatrical performance of the highest order. With every detail carefully considered, the S/850 delivers a level of power, nuance, and scale that redefines what’s possible in its class.

S/850 drivers now feature lightweight pure carbon-fiber center caps, replacing the solid aluminum moldings of earlier models. These caps reduce moving mass while stiffening the cone, resulting in explosive dynamics and the ability to resolve the quietest passages with delicacy and nuance. Feather-light yet rigid, they extend performance at both extremes—a hallmark of REL design.

Monoblock Slam, Class D Efficiency
The S/850’s amplifier delivers the slam of massive Class A/B monoblocks while harnessing the efficiency of a modern Class D output stage. Supported by a robust traditional power supply, it produces 850 watts of continuous output and can surge to 1,000 watts during demanding peaks, ensuring ample headroom for both music and theater. Upgraded input filters, equipped with the same thin-film capacitors used in REL's flagship designs, introduce a new level of transparency and refinement previously unheard of in this class. Together, these advancements create dramatic improvements in clarity, sound staging, and sheer authority—an amplifier that blends brute force with finesse to anchor the performance of the entire Serie S line.

Analog Filtered to Perfection
REL chose analog because it is the only way to achieve truly natural sound. All REL input filters are 100% analog—among the fastest ever offered in a subwoofer. At the core is REL's renowned High Level Input, which connects directly to the speaker outputs of your main amplifier. This doesn’t draw power; instead, it carries the full sonic signature of your system, allowing REL to blend seamlessly with your speakers—a quality reviewers have praised for decades.

For systems where High Level isn’t possible, REL's low-level input uses the same analog filter circuit, available via both RCA and XLR connections, to deliver the speed, naturalness, and integration REL is known for. And in theater or dual-use systems, REL uniquely allows High Level and .1/LFE to run together—so music benefits from natural integration, while movies deliver the full impact intended by the mix.

• 850-watt Linear Class D Amplifier
• 12" CarbonAlloy™ Active Driver with 12" Long-Stroke Passive Radiator
• Music & Theater Systems, Medium-to-Large Rooms
• Stereo Pairs & Line Arrays
• Optional Premium Wood Grille Available

• TYPE:  Front-firing active driver, down-firing passive
• ACTIVE DRIVER SIZE & MATERIAL:  12 in. (305mm) long-throw, CarbonAlloy™ cone structure, die cast alloy chassis
• PASSIVE RADIATOR SIZE & MATERIAL:  12 in. (305mm), Carbon/Carbon flat cone structure, steel chassis
• LOW FREQUENCY EXTENSION:  -6dB at 19Hz
• INPUT CONNECTORS:  High Level Neutrik Speakon, Low Level (2) RCA, (1) LFE RCA, (1) LFE XLR
• OUTPUT CONNECTORS:  High Level Neutrik Speakon, (1) Low Level RCA, (1) LFE RCA or (1) LFE XLR
• POWER OUTPUT:  850 watts (RMS)
• AMPLIFIER TYPE:  Linear Class D
• WIRELESS CAPABILITY:  REL AirShip Direct (sold separately)

DIMENSIONS

• W x H x D:  19.25 x 16.125 x 21.25 in (488 x 410 x 540 mm)
• NET WEIGHT:  93.5 lbs. (42.5 kg)
• FINISH:  Piano Black Lacquer, Gloss White Lacquer 8 coats
• LINE ARRAY CAPABLE (Y/N):  Y