REL Reference No. 35 Subwoofer

The REL Reference No. 35 is a sealed 12-inch subwoofer that pairs a re-engineered Pure Carbon Fiber driver with a new 900-watt Class AB/D amplifier built around a 17-pound toroidal transformer. It reaches 17Hz at -6 dB in room, and REL says it plays louder than its previous-generation 15-inch Reference flagship. It keeps the exact dimensions of the No. 31 it replaces, so it can join an existing No. 31 Line Array.

Key Features of the REL Reference No. 35

• 12K Pure Carbon Fiber Driver: A 12-inch (305mm) long-throw cone woven from 12,000-filament carbon bundles, up from the No. 31's 6K weave, for a stiffer and more self-damped cone.
• 12mm More Travel Each Way: A new cast-aluminum frame, stiffer spider and redesigned surround give the cone an extra 12mm of excursion in each direction.
• 900-Watt Class AB/D Amplifier: A Class A/B power supply with a 17-pound toroidal transformer feeds a Class D output stage, 900 watts RMS.
• 17Hz In-Room Extension: -6 dB at 17Hz in room from a closed-box, front-firing design.
• Reference Remote with Dual Parametric EQ: Gain, crossover, .1/LFE gain, phase and two bands of parametric EQ, all adjustable from the listening seat, then lockable.
• No. 31 Array Compatible: Same exact dimensions as the No. 31, with knurled leveling cylinders under the front rails for stacking in Reference Line Arrays.

What changed in the No. 35's 12-inch driver?

Almost everything. REL rebuilt the No. 35's 12-inch Pure Carbon Fiber driver around a new cast-aluminum frame, a stiffer spider, a redesigned surround and an upgraded magnet system, adding 12mm of travel in each direction. The cone moves from a 6K carbon weave to 12K, bundling 12,000 filaments into each fiber.

The reason is the amplifier. REL says the output available from the new Class AB/D stage placed demands on the driver that no previous 12-inch REL had faced, so the frame, spider and surround were reworked to keep the cone concentric and under control at full excursion. The finer 12K weave is stronger and more self-damped than the No. 31's 6K cone, which REL credits with a quieter cone and greater dynamic contrast. The cone keeps REL's inverted carbon fiber center cap and sits in a die-cast alloy chassis.

How does the Class AB/D amplifier work?

It splits the job in two. A traditional Class A/B power supply, built around a 17-pound toroidal transformer, supplies the current reserves, and a Class D output stage delivers that power with speed and efficiency. The result is 900 watts RMS without the heat and power draw of a conventional amplifier of that size.

REL designs its amplifiers with deliberate headroom beyond what normal playback needs, so the No. 35 has current in hand for sudden peaks in music and film instead of straining as demand rises. The power rating matches the No. 31's 900-watt Class D amplifier. What changed is the Class A/B power supply behind the output stage. REL says the new generation reproduces bass below 25Hz with greater amplitude and less apparent effort than the previous one.

Can the No. 35 join an existing No. 31 Line Array?

Yes. The No. 35 keeps the exact dimensions of the No. 31, so it can anchor a Reference Line Array that already includes No. 31 models. REL rates each No. 35 at more than 3 dB of additional output per unit in an array, with deeper extension, and precision-knurled leveling cylinders under the front rails set each unit level for stacking.

A Reference Line Array stacks several subwoofers vertically on each side of the system. REL's argument is that spreading the bass through the height of the room energizes the space more evenly, which frees the main loudspeakers and opens the soundstage well above the bass range. Daisy-chaining a stack uses REL's Bassline Blue Line Array Connectors.

The No. 35 Cabinet

The No. 35 uses the same cabinet construction as the No. 36 in the 12-inch Reference proportions. Its continuous curves, inspired by classic wooden runabouts, roll over the top into the rear corners, and internal bracing laid out like a ship's ribs keeps it rigid. It is finished in twelve coats of hand-rubbed piano black lacquer.

The string grille follows the cabinet's curves instead of sitting flat across them, carbon fiber trim ties the exterior to the driver inside, and triple-plated stainless-steel handles anchor into thick plates of milled aluminum.

High Level Connection, .1/LFE and AirShip Direct

The No. 35 takes REL's High Level connection for two-channel music and the .1/LFE input for film at the same time, so one subwoofer serves both. High Level feeds it the same signal your amplifier sends to your speakers, which is how REL matches the main speakers' tonal character and timing.

For a wireless setup, the optional REL AirShip Direct plugs straight into the rear panel and carries High Level and .1/LFE together with zero digital compression, using discrete Texas Instruments ADC and DAC chipsets.

The REL Reference Remote

Every critical setup control is on the included Reference Remote: High Level or Low Level gain, crossover, .1/LFE gain, phase and Dual Parametric EQ. That means the No. 35 gets tuned from the listening chair while music plays, and once setup is done the remote can be switched off to lock the settings.

The Listening Room Difference

We're a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on exceptional service and relentless passion for hifi. Whether you're visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don't just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

REL Reference No. 35 Specifications