REL No.31

The REL No.31 represents a defining moment in subwoofer engineering — a Reference-class instrument that draws directly from REL's flagship No.32 lineage, delivering performance of a scale and authority that redefines what a single subwoofer can achieve. Built without compromise and finished without concession, the REL No.31 is a statement of intent from a company that has spent decades perfecting the art of low-frequency reproduction.

NextGen 7 Class D Amplification

At the heart of the REL No.31 sits the same NextGen 7 Class D amplifier platform developed for the No.32 — configured here to deliver 900 watts of continuous power. This is not raw power for its own sake; it is the precise, controlled authority required to drive a 12-inch pure carbon fibre driver to its full potential without strain, without compression, and without the colouration that lesser amplifier designs introduce at high excursion levels. The result is bass that arrives with effortless realism at every listening level.

Pure Carbon Fibre Driver

The REL No.31's 12-inch driver is formed from pure carbon fibre — a material chosen for its exceptional stiffness-to-weight ratio and its ability to remain acoustically inert under extreme mechanical stress. Paired with a 3-inch voice coil and a 13-pound magnetic structure, the driver assembly delivers a level of low-frequency precision and dynamic authority previously unsurpassed at this price point. Every transient is rendered with the speed and accuracy that high-resolution music demands.

LimitLess Limiter Technology

REL's proprietary LimitLess Limiter technology sets a new standard in dynamic headroom management. Rather than constraining the amplifier's output prematurely — as conventional limiting circuits do — LimitLess monitors and manages the amplifier and driver in concert, preserving dynamic peaks and protecting the system without audible intervention. The REL No.31 plays louder, digs deeper, and remains composed under pressure in ways that conventional subwoofer designs cannot match.

Dual Parametric Filters

Achieving seamless integration between a subwoofer of this capability and a main loudspeaker system requires tools of equivalent sophistication. The REL No.31's dual parametric filters provide the precision necessary to align the subwoofer's output with the acoustic characteristics of any room — addressing specific room modes with surgical accuracy and ensuring that the REL No.31 disappears into the soundstage, augmenting rather than announcing itself.

Line Array Capability

The REL No.31 is fully Line Array compatible, supporting configurations of three or five units — a capability that transforms an already formidable subwoofer into a reference-grade bass system of extraordinary scale and uniformity. For those building the pinnacle of a home theatre or two-channel reference system, the Line Array configuration delivers levels of low-frequency authority and room-filling presence you will not have encountered before.

Reference Finish and Craftsmanship

The REL No.31 is finished in 12 coats of high-gloss Piano Black Lacquer, applied over curvilinear radius sidewalls that are as structurally purposeful as they are visually striking. The string grille design completes a cabinet that earns its place in any serious listening environment. A REL Reference Remote Control is included as standard, and every REL No.31 is backed by a three-year warranty and REL's lifetime customer support.

Technical Specifications

Who Is It For?

The REL No.31 is built for the listener who will accept nothing less than Reference-class bass performance — whether in a two-channel system of the highest order or a home cinema installation where low-frequency authority is non-negotiable. It rewards serious amplification, serious loudspeakers, and serious rooms. If you are ready to hear what your system has been missing at the deepest levels, the REL No.31 is the instrument to reveal it.

Buying from Martins Hi-Fi

Martins Hi-Fi has been in Norwich since 1968. Elizabeth Gould runs the business today, and we stock only brands we have heard properly and stand behind. The REL No.31 can be demonstrated at our Norwich showroom — speak to Dave or Chris, who can advise on integration with your existing system and guide you through Line Array configuration if you are building a multi-unit installation. If you are considering the REL No.31 alongside its flagship sibling, the REL No.32 is also available to hear at Martins Hi-Fi.

For wireless connectivity options, we also stock the REL AirShip MKII Wireless and the REL Arrow Wireless — both compatible with REL Reference subwoofers. Contact us at [email protected], call 01603 627010, or WhatsApp on 07554 687137. You can read more about how we work on our Why Martins Hi-Fi page. We are at 85–91 Ber Street, Norwich, NR1 3EY.