REL S/812 subwoofer review

The new Serie S range of subwoofers from REL is 
more than just a simple revision of its previous incarnation. Never a company to do things by half, the new lineup represents a total transformation of its mid-sized class 
of subs. The S/812 tested here (£2,300) tops the upgraded range, which also includes the smaller S/510 (£1,800).

The cabinet has been completely designed to be lower, wider and deeper, with dimensions based on REL’s Reference Series. There’s a gunmetal-grey badge on the top and chrome handles at the sides, which make moving the heavy S/812 considerably easier. There’s also a sizeable black fabric grille that covers a matching gunmetal driver proudly bearing the REL logo.

The more traditional chunky four feet have been replaced with ultra-stable rails that serve two purposes: first they provide better support; and secondly they cantilever the main cabinet forward allowing it to seemingly float in space. The S/812 certainly oozes high-end charm, with a choice of gloss piano black 
or gloss white lacquer finishes (and a total of 12 coats).

There’s increased power thanks to NextGen5 amplification, with the S/812 rated at 800W and able to peak over 1,000W. There are revised filters – first used in the HT/1508 – that, says REL, tailor the LFE channel to deliver almost twice the output below 40Hz. And since this is a REL sub there are high- and low-level inputs, 
and the promise of a musically natural performance.

The forward-firing 12in driver uses a lightweight ContinuousCast alloy cone that’s been upgraded to handle the increased power. An ultra-lightweight backing of pure carbon fibre has been placed at the rear to stiffen and strengthen it. The aluminium cone and carbon fibre backing are so incredibly light, boasts REL, that the heaviest element is the glue between them.

A downward-firing 12in carbon 'SuperProgressive' passive radiator again uses a new design intended to produce extremely long travel while retaining the variable stiffness of its suspension. The thinking here is that it enables the S/812 to act like a sealed-box compact 
12in design at low volume, but still deliver bass down to 19Hz when pushed. At the rear are the inputs, including high-level Neutrik Speakon, low-level stereo phono, and LFE (phono and balanced XLR) connections. There are also high-level Neutrik Speakon and LFE (phono and XLR) outputs.

Otherwise the back plate is surprisingly sparse, with just two switches (On/Standby, and 180-degree phase), and knobs for high/low/LFE levels and crossover. The Serie S subs are also compatible with REL's new wireless transmission system (AirShip).

These are the first mid-sized RELs designed to be stackable, thanks to special fixtures and included metal plates. You can safely stack and lock S/812s up to three units high. That sounds bonkers but there is logic in REL’s madness. In the real world, bass has width, depth and height; by stacking these subs you can create bigger bass presence from a smaller footprint.

Two 'line arrays' at the front of the room is an acquired taste – the cost and space required for double stacks of three subs is prohibitive for most people. It’s also better suited to stereo; for home cinema you’ll likely get more balanced bass by putting a sub in each corner of the room.

I took a slightly more traditional (and realistic) approach to installing the single S/812 I was testing, 
and simply placed it at the front of my room between 
the front left and centre speakers. I used the mono LFE input, but the subwoofer comes with a 10m Neutrik Speakon cable for those who fancy a simultaneous high-level connection. A few gripes before we get on to the good stuff. 
I was disappointed the writing on the rear panel isn’t also upside-down. REL does this on other models and it makes things easier when peering down the back. It’s also hard to tell where the control knobs are set, indentations or a raised line would help. Finally, the setup is very manual, with no remote control or smartphone app offered – both are common at this price.

REL S/812 performance
Getting down to business [nice pun – Ed], the S/812 
is an astonishingly good subwoofer that delivers thunderous bass with a surprising amount of subtlety 
and grace. Naturally there are times when you want your sub to level the foundations, and if that’s the case this REL has you covered.

Popping on Godzilla: King of the Monsters (4K Blu-ray) provides plenty of opportunity to see what this sub is made of, and I’m pleased to report it’s not found wanting. The monster’s roar and footsteps herald the start of the film, and the S/812 digs deep before literally shaking the room. From then on, it’s an ultrasonic assault of seismic proportions as each successive titan indulges in 
city-destroying fisticuffs with poor old Godzilla. There’s an epic nature 
to the LF as crumbling buildings 
and erupting volcanoes pummel you into submission, and the detonation of a nuclear device in the movie sends a low-frequency shockwave through the room.


However, what really impressed me isn’t just the power and depth of the bass, but also its nimbleness. The S/812 can 
deliver the kind of fast and precise low-end that not only suits music replay, but also picks out key low- frequency effects in the best movie soundtracks. Load up Overlord (4K Blu-ray) and the opening parachute drop and you’ll see what I mean. The exploding flak hits with alarming precision, despite the constant drone of 
the Dakota’s engines.

When the plane is destroyed the resulting fireball seems to move through the room, propelled by the S/812's 12in driver. Then the main protagonist tumbles through the air and ordinance explodes all around him with a percussive thump you feel deep in your gut. It’s an engrossing sequence that is utterly enhanced by the deep reach 
and controlled delivery of the S/812.

In fact, it was so good that I immediately thought 
of another WW2 film, and reached for Fury (Blu-ray). 
What better way to test a subwoofer than a tank battle between three Shermans and a Tiger? This brilliantly visceral scene is taken to another level by the REL. 
Each tank acquires a distinctive low-end rumble so deep 
I was expecting their tracks to tear up my carpet, but at 
the same time the sub clearly delineates the tighter slam of explosive shells ripping through plate armour. The bass here is deliberately brutal, but the S/812 produces it with poise and authority.

REL S/812 verdict
This is in essence what you’re paying for when choosing a high-end subwoofer. There are plenty of cheaper subs, and some can even go nearly as deep as the S/812, but they’re unable to mine such depths 
while remaining so composed. Good bass shouldn’t dominate, 
it should be an integral part of your cinema soundstage, adding low-frequency impact where needed. This is what the REL S/812 achieves so well – it goes deep with control, shows effortless speed and agility, 
and can seamlessly blend with your other speakers to enhancing whatever you’re watching. It misses out on some feature finery, but hits hard where it counts.

HCC Verdict: 5/5

REL S/812

Price: £2,300

We say: Cutting-edge innovations deliver enormous power and surprising subtlety, resulting in a serious sub that sounds big and looks classy.


Drive units: 1 x 12in forward-firing ContinuousCast alloy driver; 1 x 12in down-firing passive radiator
Enclosure: Sealed Frequency response (claimed): Down to 19Hz (-6dB)
Onboard power (claimed): 800W
Remote control: No
Dimensions: 455(h) x 430(w) x 514(d)mm
Weight: 34kg

Features: High-level Neutrik Speakon, low-level stereo phono, LFE phono and LFE XLR inputs; high-level Neutrik Speakon, LFE phono and LFE XLR outputs; high/low and LFE level controls; crossover control; 180-degree phase switch; automatic standby option; NextGen5 amplification; compatible with REL AirShip wireless system; stackable rail design

REL Acoustics