REL Acoustics

No.31

Introduced 2022$9,000 MSRP

The No.31 is a sealed-box, single-driver reference subwoofer built around a 12-inch long-throw carbon-fiber driver and a 900-watt NextGen 7 Class D amplifier — effectively a scaled-down version of REL's flagship No.32 aimed at rooms with space constraints (source: [REL Acoustics](https://rel.net/products/no-31), [Stereophile](https://www.stereophile.com/content/rel-no31-powered-subwoofer)). It features REL's dual parametric EQ, a distinctive teardrop-shaped piano-lacquer cabinet, and support for REL's vertically stacked line-array mounting system (source: [REL Acoustics](https://rel.net/products/no-31), [Pursuit Perfect System](https://www.pursuitperfectsystem.com/rel-no31-subwoofer-review/)).

MSRP

$9,000

Used market · Good

$6,250

-31% vs MSRP

as of Sep 1, 2026

Sell or trade this Add to my system

MSRP to used market

From $9,000 at launch to $6,250 today.

Specifications

Finish: Piano Black Lacquer, 12 coats
Weight: Net 114.5 lbs (52 kg); shipping weight 156 lbs (71 kg)
Dimensions: 25 1/8 × 17 × 28 1/2 in. (638 × 435 × 720 mm)
Enclosure type: Closed box (sealed), front-firing driver
Inputs outputs: High-Level Neutrik Speakon, Low-Level (2) RCA, (1) LFE RCA, (1) LFE XLR in; High-Level Speakon, Low-Level RCA, LFE XLR, Line XLR out
Amplifier power: 900 watts RMS, NextGen 7 Class D
Dimensions w h d: 25 1/8 × 17 × 28 1/2 in. (638 × 435 × 720 mm)
Driver complement: 1× 12 in. (300mm) long-throw carbon fiber cone driver with inverted carbon fibre centre cap, die-cast alloy chassis
Frequency response: 17 Hz at -6 dB low-frequency extension (claimed 17Hz–200Hz)
Wireless capability: REL AirShip II (sold separately)