REL - No.31 - Reference Powered Subwoofer

REL No.31 distills the technologies, craftsmanship, and performance philosophy of the flagship No.32 into a more space-friendly design without sacrificing the speed, transparency, and emotional connection that define the Reference Series. Created for discerning listeners who demand world-class bass performance in environments where the larger No.32 may not be practical, No.31 delivers extraordinary dynamics, nuance, and low-frequency authority from a beautifully engineered compact chassis.

At its core is a 12-inch pure carbon fiber driver powered by REL's NextGen 7 amplifier platform. Combined with advanced room-tuning capabilities, Line Array compatibility, and the included REL Reference Remote, No.31 offers a level of refinement and system integration rarely found in any subwoofer regardless of price.

DESIGN

No.31 shares the same design language as the flagship No.32, featuring elegant plated handles recessed into sculpted elliptical side panels, gently curved cabinet walls, and REL's distinctive string grille design that promotes unrestricted airflow while minimizing acoustic coloration.

Finished in twelve hand-applied coats of Piano Black lacquer, No.31 delivers a luxurious appearance that complements the finest listening rooms and high-end audio systems. Despite its more compact footprint, it retains the visual presence, structural integrity, and premium craftsmanship expected of a Reference Series component.

DRIVER

At the heart of No.31 is a 12-inch pure carbon fiber long-throw driver utilizing an inverted carbon fiber center cap and a substantial die-cast alloy chassis. Driven by a specially wound 3-inch voice coil and a massive 13-pound magnetic structure, the driver delivers exceptional excursion capability, speed, and control while remaining composed even at extreme output levels.

The result is bass reproduction that combines visceral impact with remarkable delicacy, offering both effortless dynamic authority and the ability to reveal subtle musical textures and low-level detail.

AMPLIFIER

No.31 utilizes REL's advanced NextGen 7 Class D amplifier platform, derived directly from the flagship No.32. Rated at 900 watts RMS, the amplifier is optimized specifically for the 12-inch carbon fiber driver to deliver maximum performance while ensuring long-term reliability.

Advanced technologies include REL's proprietary LimitLess Limiter™, which allows the amplifier to approach its limits without audible compression, along with dual parametric filters for precise in-room tuning. Users can fine-tune deep bass response and upper bass integration to achieve seamless blending with the main loudspeakers and optimal room performance.

WIRELESS

No.31 is compatible with REL's optional AirShip II wireless system, providing high-performance wireless connectivity while preserving the speed, transparency, and dynamics expected from a Reference Series product.

REFERENCE REMOTE & LINE ARRAY

Included with No.31 is REL's beautifully crafted Reference Remote Control, allowing precise adjustment of gain, crossover, phase, LFE level, and dual parametric equalization directly from the listening position. Designed specifically for the Reference Series, it provides an elegant and intuitive interface for achieving perfect system integration.

No.31 also supports REL's advanced Line Array architecture, allowing up to three—or even five in exceptionally large spaces—subwoofers to be vertically stacked per channel. This unique configuration dramatically improves image height, scale, dynamics, and overall realism while maintaining individual control of each subwoofer within the array.

WHAT'S IN THE BOX

• No.31 Reference Subwoofer
• Protective Grille
• 6 ft. AC Power Cord
• 32 ft. Neutrik Speakon Cable
• Reference Remote Control
• (2) AAA Batteries
• Line Array Mounting Hardware
• User Manual & Warranty Information

SPECIFICATIONS / DIMENSIONS

Type: Closed Box, Front-Firing Driver
Active Driver: 12 in. (300mm) Long-Throw Carbon Fiber Cone with Inverted Carbon Fiber Center Cap, Die-Cast Alloy Chassis
Passive Radiator: None
Amplifier Power: 900 Watts RMS
Amplifier Type: NextGen 7 Class D
Low Frequency Extension: 17Hz (-6dB)
Inputs: High Level Neutrik Speakon, Dual RCA Low Level, LFE RCA, LFE XLR
Outputs: High Level Neutrik Speakon, Low Level RCA, LFE XLR, Line XLR
Wireless Capability: REL AirShip II (Sold Separately)
Dual Parametric Filter: Yes
Available Finish: Piano Black Lacquer
Finish: 12-Coat High Gloss Piano Black Lacquer
Protection System: Fully Electronic Set Safe
D.C. Fault Protection: Yes
Output Short Protection: Yes
Mains Voltage: 220-240V / 110-120V Depending on Market
Fuse Rating: 7 Amp Semi Delay (230V), 15 Amp Semi Delay (115V)
Included High-Level Cable: 10 Meter (32 ft.) Neutrik Speakon
Dimensions (W x H x D): 25.125 x 17 x 28.5 in. (638 x 435 x 720 mm)
Net Weight: 114.5 lbs. (52 kg)
Shipping Weight: 156 lbs. (71 kg)