REFERENCE SERIES

No.31

$7,500

Expertly enhanced and meticulously refined to provide an exhilarating experience.

  • 900-watt NextGen 7 Class D Amplifier
  • 12" Carbon Fibre Driver
  • Line Array Compatible
Setup:One Subwoofer
No.31
  • Single Subwoofer
$7,500
Find It Locally

Delivering More Than Sound

3 Year warranty

3 Year warranty

Lifetime Customer Support

Lifetime Customer Support

Learn More

No.31 exists to satisfy the needs of those who crave the finest yet have space limitations. Whilst some can afford our flagship No.32 model, it is larger and deeper than some rooms can accommodate. How can you best deliver No.32’s sound quality, build quality, and thoughtful features with a more compact footprint? Enter No.31.

No.31 exists to satisfy the needs of those who crave the finest yet have space limitations. Whilst some can afford our flagship No.32 model, it is larger and deeper than some rooms can accommodate. How can you best deliver No.32’s sound quality, build quality, and thoughtful features with a more compact footprint? Enter No.31.

Design

Perfection Repeated

No.31 matches No.32’s design stroke for stroke, yet somehow it manages to look more svelte, crouching closer to the floor—almost feline in its grace. The elegant plated handles inset into an ellipse is retained, as is the string grille that permits vast amounts of air to explode into your room without creating noise like cloth grilles can. No.31 features the curvilinear radius to the sidewalls that define both its performance and its character. But the reduction in visual and actual three-dimensional physical mass is remarkable. No.31: when the best must be delivered in a smaller space.

Driver

Drive This

The incredible excursion of the 12” pure carbon fibre driver allows it to play as loud as its larger stablemate. Yet, the No.31 possesses the tactility, nimbleness, and attack that only the greatest subwoofers have ever been able to deliver. Also, its sonic signature works in modestly-scaled rooms and with a vast range of fine speakers. The driver is accelerated by a specially wound 3” voice coil driven by a 13-pound magnetic structure; even near its limits, the voice coil remains solidly inside the gap. It is this visceral power, coupled with great delicacy and nuance, that is No.31’s signature.

Amplifier

Amplified Perfection

No.32’s NextGen 7 Class D 1,000 watt amplifier also lives inside No.31, only limited to 900 watts to ensure the perfect complement to the 12” bass engine within No.31. This allows the maximum dynamics to be delivered while ensuring a long, cheerful life for both components. Here too, the LimitLess Limiter,™ which permits the amplifier to tiptoe right up to its limit without audible compression is part of the magic, conveys a rhythmically effortless quality. Also, its dual parametric filters allow precise micro-tuning; the deepest bass is slightly reinforced, while the upper ranges of bass can be gently trimmed to ensure a brilliantly rendered transition from bass to the main speaker. The electronic design of the reference range is itself artistry.

Line array

Arrayed for Battle

No.31 permits the same vertically stacked line array as the ultimate No.32. It delivers transformative performance that no competitor has been able to. For those who have been seeking the ultimate musical and theatre experience, Line Arrays unlock the final dimension of system reproduction. Audiophiles have chased three-dimensional sound for years, yet they have missed the simple fact that the height—not the depth—of image is the missing link. By creating products that are designed to be stacked 3 (or in exceptionally tall rooms, 5) units high while retaining individual crossover and gain control of each subwoofer in the array, REL has created a masterpiece that finally delivers what the most experienced audiophiles have been chasing for the past 40 years.

How to Build Up to a Line Array.

How to Setup and Dial in a Line Array.

Remote

A Remote Like No Other

Take control of your No.32 by grasping the REL Reference Remote Control. Immediately, you will be struck by the perfect fit in your palm, the result of careful thought and numerous generations of trial-and-error fittings during prototype development. The second reaction to it is the awareness of its mass, which conveys its quality, permanence, and immutability. It tells you, “I am a thing of substance, of quality. Pay attention, what you do next matters.” If you have owned a REL in the past (and fully 90% of Rel Reference owners are), all the familiar controls are right at hand, exactly where you’d want them. High (or low if using active speakers) level gain sits comfortably to the right side, the crossover rests in the middle, and .1/LFE gain is off to the left.

Below are three lovely metal toggle switches handle the critical setup functions. The remote’s on/off switch is at the bottom. It is both as out of the way as possible and remains on once turned on and in use during setup without being accidentally turned off. In the middle sits the phase control. This is used only initially to determine the correct 0 or 180 degrees of phase. Additionally, the top access to the Dual Parametric EQ-marked with A and B—permits the flattest, deepest bass and, at the other end of the bass frequencies, the fine-tuning of crossover behavior. This gives you the perfect blending of subwoofer to main speakers and any vestiges of room-generated boom and resonance can be gently trimmed away.

REL’s Reference Remote reminds you of the perfect butler—always immaculate, indispensable when called upon, then quietly set aside until a future time when perhaps additions or further improvements to one’s system further require its services.

Specifications
Technical Specifications
Type

Closed box, front-firing driver

Active Driver Size & Material

12 in. (300mm) long throw, carbon fiber cone with inverted carbon fibre centre cap, die cast alloy chassis

Passive Radiator Size & Material

N/A

Low Frequency Extension

17Hz at -6 dB Low Frequency

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 XLR, (1) Line XLR

Power Output

900 watts (RMS)

Amplifier Type

NextGen 7 Class D

Wireless Capability

REL AirShip II (sold separately)

Dual Parametric Filter

Yes

Finish

Piano Black Lacquer, 12 coats

Protection System
Fully Electronic Set Safe

Yes

D.C. Fault

Yes

Output Short

Yes

Mains Input Voltage

220-240 volts, 110-120 volts for certain markets

Fuses

7 Amp semi delay 230 volts operation, 15 Amp semi delay 115 volts operation

Supplied Accessories
Mains Lead

Yes

Neutrik Speakon

Yes (10 Meters Nominal)

Interconnect

-

User Manual

Yes

In the interest of product development, REL Acoustics Limited reserve the right to vary these specifications without notice.

Dimensions
W x H x D

25 1/8 x 17 x 28 1/2 in
(638 x 435 x 720 mm)

Net Weight

114.5 lbs (52kg), shipping weight - 156 lbs (71kg)

Awards & Industry Reviews

TONE Audio
TONE Audio

"The No.31 is faster, more nimble. If you only think of the low-frequency augmentation provided by a subwoofer as a single sonic shade, be prepared to have your paradigm reset." TONE Audio

- TONE Audio

Read Article

hi-fi+
2022 Award

"To say I was impressed by the REL No 31 is an understatement, but curiously the No 31 is all about understatement. Sure, it can move a lot of air when called upon, but it’s at its best when making great loudspeakers sound so much better than you might expect. For all its size and weight and power, the No 31 is a truly graceful performer able to bring out the best in your system."

- hi-fi+

Read Article

Home Cinema Choice
Best Buy

"REL's No.31 lives up to its Reference moniker, delivering premium LFE slam and speed alongside unrivalled bass detail that enhances the entire soundfield."

- Home Cinema Choice

Read Article

"Build a WOW System! REL Subwoofer Six-Packs"

- ListenUp

Read Article

"I LOVE these SUBWOOFERS REL's BEST No.31."

- Pursuit Perfect System

Read Article

"REL has really created something magical with these. I am almost lost for words regarding their level of performance and build quality. The engineers and designers at REL Acoustics have created a masterpiece. Thank you."

- Sound Stage Australia

Read Article

Pursuit Perfect System
Best of 2023

"The REL No.31's. The only product I could use that made my system infinite better in this room. The 31's are very, very special."

- Pursuit Perfect System

Read Article

No.31
No.31
No.31

What's in the box

  • Reference No 31 Subwoofer
  • Grille
  • 6' AC Power Cord
  • 32' Neutrik Speakon cable
  • User Manual & Warranty Information
  • Reference Remote
  • Batteries (AAA x2)
  • Line Array Mounting Hardware

The Right REL for You

No.32
REFERENCE SERIES

No.32

$10,000
29 1/4 x 21 x 32 1/8 in.
(743 x 540 x 816 mm)
1,000 watts (RMS) NextGen 7 Class D
N/A
15Hz at -6 dB Low Frequency
Carbon Special
SERIE S

Carbon Special

$4,699
17 x 18 x 21.25 in.
(430 x 455 x 539 mm)
800 watts (RMS). Up to 1,000 watts (RMS) NextGen 5 Class D
12 in. (300mm), Carbon/Carbon flat cone structure, steel chassis
-6 dB at 19Hz Low Frequency (in Room)
We’re looking for stars!
Let us know what you think

Learn & Explore The No.31

View All Articles & Videos

No.31 Product Overview

The Reference Compact

There’s a Reason They’re Called Reference

Superior by Design