Note: At the time of the preview the Sonos SUB was available for £499-599. but post-Brexit pricing has nudged it up to around £699 in most stores.

Sonos is perhaps the best-known maker of multi-room audio kit, and in recent years it has done its best to appeal to a new audience – one without pockets overflowing with cash. Boxes like the Play:3 let you get on the wireless streaming bandwagon fairly cheaply, and the Sonos system lets you expand your setup whenever you like. The new Sonos SUB is a way to dramatically increase the power of a Sonoa rig.

While you’re here, check out the Sonos Beam smart soundbar, which features Amazon Alexa, Google Assistant and Apple Siri.

Design
Sonos is an audio company that has always had its eye on the lifestyle angle. After all, multi-room audio is fundamentally a “lifestyle” thing. As such, the Sonos SUB subwoofer is predictably a lot smaller than most hi-fi subs.

Just 15cm thick and around 40cm high, it’s not something that will dominate the floor of your living room. And Sonos has made sure it’s not the squat cube that most subwoofers are. Finished in nine layers of flawless glossy paint and with a stylish-looking silver cut-out in the middle, it could live a second life as a modern take on an art deco stool.

The cut out in the middle is where you find the two drivers. Part of the reason why the Sonos SUB can stay so slim is that these drivers are not precisely round but stretched-out vertically.

They are also smaller than those of most subs – but there are two of them. They fire directly at each other, as if part of some sort of sub-bass Mexican stand-off. Sonos claims this action cancels the force produced by the speakers. Above and below the drivers are ports that help to siphon-off the expanse of air pushed out by the speakers.

This design and the special composite that makes up the SUB’s body deadens much of the vibration caused when pumping-out those low-frequency bass notes – the thing only vibrates lightly in use, even when cranked up.

This design also makes it less picky than most hi-fi subs about where it’s positioned. We heard the Sonos SUB sat upon a table – and although jamming the cut out right against a wall will affect bass response, it shouldn’t make it boom through the roof. Even by the standards of “style” 5.1 systems, this subwoofer is discreet and attractive.

To begin with, the SUB will come in just the glossy black finish, but a cheaper matt edition is due out later in the year – those pristine layers of glossy coating don’t come cheap. The matt version will sell for £499, while the glossy is £599.

Setup  
Fully integrated into the Sonos system, setting up a SUB is similar to the setup of any other piece of Sonos equipment. There’s the standard communicator button on one of its sides, and it automatically changes its behaviour depending on the components it is used with. When paired with a Play:3, the crossover will be slightly different from the Play:5 thanks to its smaller drivers, for example.

The Sonos app also gives you a reasonable amount of control over the SUB. There’s a setup wizard of sorts that helps to mitigate for the sonic peculiarities of the room it’s in, and a separate gain control. As with the other Sonos products, though, the clever bits inside area meant to do most of the work.

This also means that it’s not compatible with the non-amped Sonos boxes, such as the ZP80. The perfect pairing-up it’s capable of is one of the best things about the SUB – in our demo it proved a near-seamless addition to a compatible Sonos rig.

Performance
We heard the Sonos SUB working its magic along with a pair of Play:3 boxes. These use a pair of 3in main drivers, which are too small to be able to create thunderous bass at high volume.

A pair of them is enough to make quite a musical racket, but the difference between use with and without the SUB was huge. As satisfying as they are in tandem, the Play:3s sounded relatively thin once the SUB was disengaged, as well as strained at high volumes. To our ears the bass of the subwoofer seemed a tad too much at the default volume, but as you have quick and easy control over the gain level, tailoring it to your own preferences only takes a few seconds.

The Sonos family

Value
At £699, though, the Sonos SUB re-awakens the problem the company used to suffer from. A pair of Play:3s and the SUB will set you back more than a thousand pounds. For that price, you could buy a dedicated stereo amp and a pair of high-end floorstanders like the Monitor Audio BX6.

The Sonos setup may be able to produce more bass, but in pure fidelity terms, it would be an easy win for the Monitor Audio rig. Of course, that doesn’t take into account the great benefits of the Sonos infrastructure – best of all being slick and easy access to streaming services like Spotify and Deezer. As with most lifestyle products, there’s a compromise involved. But this is one that’s pretty easy to live with.

We’ll be back with the full verdict on the Sonos SUB soon. It goes on sale on June 19.