Sonos Sub 4 review: the boss of bass

If you've been eyeing up the Sonos Arc Ultra soundbar as the ultimate upgrade for your TV – or perhaps you've already bought one – then how do you upgrade your Sonos system yet further? By adding a big ol' subwoofer, that's how.

The Sonos Sub 4 was announced when the Arc Ultra was revealed, designed as the perfect pairing to fit with Sonos' best soundbar and crank up the low-end delivery to an elevated extreme. Ideal for movies, music and, well, just about anything that wants daubs of bass.

The fourth-gen subwoofer from Sonos does have a new internal design, is marginally lighter weight, while sporting a matte exterior finish that denies fingerprints – unlike its predecessor. This isn't an 'upgrade' product for current Sonos Sub owners, realistically, but it is a great add-on for Arc or Arc Ultra owners who want to turn up the bass.

Sonos Sub 4: Price & Availability

The Sonos Sub 4 is available now, priced £799 in the UK, $799 in the US, and AU$1299 in Australia. That's big money for your big bass, but Sonos' subwoofers have always been pricey additions. If you're feeling the need for a sea of bass, it's possible to pair two with a Sonos soundbar – at double the asking price, of course.

You can package purchase with an Arc or Arc Ultra soundbar to knock the overall cost down a bit, or do consider the previous Sub (Gen 3) – which has seen a price reduction – or the smaller Sub Mini as alternatives which may align better with your setup. Sonos works with Sonos only, do note, so no third-party products are an option.

Sonos Sub 4 review: What's new?

Compared to the Sub Gen 3, the Sub 4 is exactly the same physical dimensions. It's a roughly 40cm square across its large side, and almost 16cm deep. It's a pretty regular subwoofer size, really, with similar equivalents such as the LG S95TR – which I also had out during Sonos testing – actually being slightly larger.

Where the Sub 4 differs from most subwoofers, however, is that it has a centralised opening in the middle of the product which you can see right through (even put your hand through) – most 'classic' subwoofers have a porthole design instead.

Sonos' method with this design is that two opposing drivers can effectively 'cancel out' any distortion. The porting is internal – but redesigned in the Sub 4 compared to its predecessor. The 'exploded view' of each subwoofer is shown on Sonos' official site (here and here) – and while that may mean difference in sound, I suspect almost nobody would be able to determine the difference.

The redesign does mean a slight shift in weight, with the 11.79kgs on the scales meaning a 1.36kg drop. Even though that's not significant from an at-home perspective, I'm sure it'll have a positive impact on the Sub 4's carbon footprint when it comes to shipping and, perhaps, cost of production too.

The biggest change in the Sub 4 that people are likely to notice, however, is that the exterior finish is now matte, not glossy like its predecessor. That might sound minor, but honestly, when I've handled the Sub Gen 3 before now, it's terrible at adsorbing fingerprint marks. It's not as though you need to touch a subwoofer often, if really at all, but this change is an obvious positive.

Sonos Sub 4 review: Setup & Sound

If you read my Sonos Arc Ultra review then you'll see I had some issues with the initial setup, but once those hurdles were cleared it was all plain sailing with a solid connection. The same was true in my Sub 4 setup: it was super-keen to be paired first, ignoring the Arc Ultra soundbar in the app, which then created a problem pairing the two. I had to reset my home router and the Sub 4 (long ol' press-and-hold on the main button) before it came good.

Once good, however, it's really good. There's no dropping in connection here, it's a sturdy companion to that Sonos soundbar. You can view the subwoofer in the Sonos app, too, and even adjust its output (+/-15) or, should you wish, turn it off with a simple touch of a virtual toggle – potentially ideal if it's for late-night viewing and you don't want your home's frame reverberating and keeping everyone awake.

Which goes to tell just how chunky the Sonos Sub 4's output is: I love bass, so I've really enjoyed the powerful low-end output from this subwoofer. It caters for frequencies down to 25Hz, which is approaching inaudible (you can feel it though!), but in those big Hollywood movie soundtracks – full of classic down-pitched 'woms' and other low-frequency rumbles – it massively enhances the audio experience.

So much so that, actually, I'm not sure the Sub 4 will be for everyone. The Arc Ultra is so good at delivering meaty bass that, for plenty of setups, it'll be more than ample. The Sub 4 massively elevates the home cinema experience, of course, but the addition of a Sub Mini might be good enough for many – that's capable of 25Hz too, it's just in a smaller package with less 'reach' for bigger spaces, really.

Sonos Sub 4 review: Verdict

Overall, the Sonos Sub 4 is the perfect companion for the Sonos Arc Ultra soundbar. Combined they create a superb home cinema experience – and if you're feeling extra flush then you can even add a pair of Sonos Era 300 speakers for true surround too.

That's the thing, y'see, you'll need to be feeling deep into your pockets for this bass upgrade – and while I think it's well worth it for that clean and impactful low-end, it'll frankly be more than everyone is going to need.

So the Sonos Sub 4 isn't one for upgraders who already own a Sonos sub – unless you're desperate for the admittedly much better-looking matte finish and its fingerprint-negating bonus – but for those upgrading their Sonos home cinema system, the Sub 4 is the boss of bass for the ultimate movies and music experiences.

Also consider

While the Sub 4 is great, the previous Sub 3 is exactly the same size, just has a glossy finish, but can purchased for less cash right now. If you don't mind wearing cashmere gloves when setting it up, it's one way to save money without any notable compromise.

If the full-size Sub models are going to be too much, then consider going smaller. The Sub Mini is a great product, with the same low frequency response, and while Sonos suggests it's not compatible with the Arc or Arc Ultra, it actually is (certainly with the former, I've not been able to test with the latter) – and will be as much as many need.