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REL Acoustics No. 31 Reference Subwoofer

REL Acoustics No. 31 Reference Subwoofer

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Regular price $7,000 In stock now!
Regular price $7,000 Sale price $7,000 In stock now!
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REL Acoustics No.31 Reference Subwoofer

A 900 W reference sub with a 12" carbon-fiber driver delivering visceral power, coupled with great delicacy and nuance.

No.31 is a pure reference model from REL, designed for those who want the best, but don't quite have the room for a No.32. No.31 delivers the classic Reference filter used in No.32, the same dual parametric filters, a driver that handles three times the power to deliver a truly thrilling experience.

No.31 features the curvilinear radius to the sidewalls that define both its performance and its character. It also permits the same vertically stacked line array as the ultimate No.32.

A 900 W Bass Engine

No.32’s 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 life for both components. REL's LimitLess Limiter permits the amplifier to tiptoe right up to its limit without audible compression. 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 incredible excursion of the 12” pure carbon fiber 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.

Complete Control

Take control of your No.31 by grasping the REL Reference Remote Control. Its perfect fit in your palm is the result of careful thought and numerous generations of trial-and-error fittings during prototype development. All the controls you need 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 metal toggle switches that handle the critical setup functions. 


  • Wireless capability via REL Airship II system, sold separately
  • Dual parametric equalizer
  • High-gloss 12-coat black finish
  • Supplied with 30' Neutrik Speakon interconnect


Type: Closed box, front-firing driver

Driver: 12" (300 mm), 2.5" (96.5 mm) long-throw, carbon-fiber cone with inverted carbon fibre center cap

Low-Frequency Extension (-6 dB): 17 Hz

Inputs: High-level Neutrik Speakon, low-level stereo RCA and XLR, LFE RCA, LFE XLR

Outputs: High-level Neutrik Speakon, LFE XLR, line XLR

Power Output (RMS): 900 watts 

Amplifier Type: Class D

Dimensions (WHD): 25-1/8" x 17" x 28-1/2" (638 x 435 x 72 mm)

Weight: 114.5 lb (52 kg)