In 2017, Sky announced the Soundbox and it generated a huge amount of interest. Not because this was (and is) the first time Sky has ventured outside its core TV product, but because of who it was partnering with to produce it – and the price.

That firm is Devialet, a French audio company that made its name not in soundbars but from its pricey audiophile Phantom wireless speakers. And when I say pricey, I'm not kidding: the Phantom family starts at around £1,400 and gets steadily more expensive from there (you'll also need two of them if you want the luxury of true stereo sound).

The Soundbox, on the other hand, benefits directly from Devialet's high-end audio expertise and yet costs less than £300. Or at least it does if you're a Sky subscriber. Since its announcement, the Soundbox's price hasn't changed and fast-forward to 2018, it's still an incredible speaker for Sky customers.

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Sky Soundbox review: What you need to know

With the pedigree of Devialet, it’s not hard to see why so many people are excited by the prospect of the Sky Soundbox. This is a speaker Sky is “discounting” from the £799 it'll cost for non-Sky customers to £299 for subscribers, and to an even more reasonable-looking £249 for those with Sky Q multiroom packages, and yet it's a speaker that inherits quite a bit of its audio technology from the pricier Phantom speakers.

Not that it looks like it from the outside, though. While the Phantom cuts a futuristic, sci-fi figure, the Devialet-made Sky Soundbox is a bit of an unassuming black brick. Its footprint is slightly larger than the Sky Q box itself, it’s wrapped in speaker cloth around the outside, with the Devialet logo adorning the front left-hand corner and the Sky logo is embossed in the centre on the top. There's no indication that there's anything special about this speaker at all.

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It is solidly made, though. Underneath is a rubber foot, designed to isolate the speaker from vibrations and to prevent it from sliding around on the top of your AV cabinet. Pick it up, and it's surprisingly heavy.

There's only one glaring problem: at 95mm the Soundbox is quite a bit taller than most soundbars. So much so that when placed in front of my TV at home it sticks up, obscuring part of the screen; I ended up clearing some space and putting on the shelf below. Of course, if you have your TV wall-mounted this won’t be a problem, but it’s certainly something to bear in mind before you get your credit card out.

Sky Soundbox review: Price and competition

Something else to bear in mind is that this is definitely not £799-worth of TV speaker. For that sort of money you can pick up a seriously good Samsung Soundbar and subwoofer set - the HW K850 - and this not only sounds better than Sky’s speaker, it also has more features, supporting Wi-Fi and multi-room streaming and Dolby Atmos.

At the £299 or £249, Sky TV customers will be paying the Sky Soundbox is far more competitive. At this price it comes up against products such as the Q Acoustics M2 (£250) or Cambridge Audio TV2 V2 which is even cheaper at £179 - and it sounds as good as any of them.

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Sky Soundbox review: Design and features

One advantage the Soundbox’s competitors do hold over it is that they’re a little more practical. The M3, for example, although still quite bulky is shorter by an inch or so than the SoundBox and is likely to more comfortably sit in front of more TVs. It also comes with a wall-mounting kit, where the Soundbox does not.

Connectivity isn’t amazing either. The Soundbox is designed, like most one-box TV speakers, to be connected series between your source (Sky Q box in this case) and your TV. Around the back in a small cubbyhole, there are two 4K UHD capable HDMI ports to enable this – one input, one output – plus an optical input for hooking up other sources.

That’s all you get in terms of audio-visual connections, though, and to my mind, it’s also a little restrictive. I’d like to have seen at least one extra HDMI input here, especially since the output doesn’t support ARC (audio return channel) for passing an audio signal back down the line - if only to keep things as uncluttered as possible. Still, the Soundbox does have that optical input, so you can route other sources such as games consoles or Blu-ray players via your TV if need be.

If the Soundbox looks simple from the outside, though, there’s plenty going on under the hood. The Soundbox has Bluetooth support so you can play tunes directly through it from your smartphone (there’s no Wi-Fi or multi-room audio support, though), and Sky has implemented a whole bunch of clever automated sound processing techniques as well.

The first of these is AVL (automatic volume level), which adapts the intensity of the sound automatically, dropping the volume subtly when action scenes kick in – a rapid burst of gunfire, for instance – the idea being you don't have to continually reach for the volume control while watching a film. It worked well during the demo, but can't be disabled, so this is probably not a speaker for the purists.

The second is something Sky is calling Q Sound; an automatic EQ mode that senses the content type and adapts the sound profile accordingly. This is enabled via the Sky Q accessibility menu (press the “?” button on the Sky Q remote) and it applies specific profiles when it detects you’re watching football (accentuating crowd noise), F1 (boosting the engine noises), cricket, boxing and movies. For all other content, it falls back to its default mode.

Finally, you get a short selection of the sort of sound profiles many soundbars offer – night mode (reduces bass), kid mode (limits volume – this thing goes seriously loud) and speech enhance – that you can layer over the top of the Q Sound processing.

It's all clever stuff and again seems to work effectively, with caveats. While the football match I was shown sounded more atmospheric with Q Sound enabled, the Formula 1 clip wasn't quite so successful, with the commentators' voices sounding a touch muffled once the processing was enabled.

A couple of other things It is worth noting, though: the volume levelling can't be turned off and is applied to all sources; both Q Sound and the audio profiles only work with content delivered via a Sky Q box.

Another annoyance is that there’s no display, just a power indicator light, so you can’t see at a glance which source you’re connected to. Instead, the Soundbox vocalises source changes whenever you press the appropriate button on its tiny remote control, saying “HDMI”, “Optical” or “Bluetooth” before engaging.

This is simultaneously beautifully simple and incredibly annoying because as well as announcing source changes, the Soundbox will also gleefully tell you when Bluetooth devices connect and disconnect, interrupting whatever’s playing at the time. So if someone walks into the living room with a paired phone in their pocket, the speaker will enthusiastically announce “Bluetooth device connected” and the tell you that the same device is disconnected if that same person wanders out of the room.

Sky Soundbox review: What does it sound like?

You’ll probably learn to live with such small annoyances, however, because the Sky Soundbox sounds great. Behind the scenes are six woofer drivers in what Devialet calls a “push-push” configuration and three full-range drivers, one facing the front and the other two facing rearwards. And this setup delivers the sort of sound pressure I’d more regularly associate with a speaker and subwoofer set.

It’s both detailed and aggressive, digs deep, goes extraordinarily loud and has the sort of even-handed delivery that sounds fantastic with movies and music alike, lifting vocals against busy backing tracks so they’re easy to hear and presenting music with warmth and drive.

Despite its size, the Soundbox also presents a pretty wide soundstage, although here we’re talking something more akin to a single soundbar rather than the depth and breadth of a full-on surround sound system. That's mainly thanks to the rear-facing full-range drivers, which fire sound backward, bouncing it off your walls and furniture.

And this is where the size and shape of the Sky Soundbox counts against it. I simply can't imagine many people will be able or willing to place the speaker in enough open space to make the most of its sideways- and rear-firing speakers. Still, it's well worth doing, because if you can position the speaker correctly it opens up the sound stage nicely; not to fully surround-sound speaker system levels but certainly, enough to compete with most single soundbar speakers.

There are some other caveats here, as well. Although good, the bass isn’t quite as deep as you’ll get from a dedicated subwoofer. Devialet says it goes all the way down to 35Hz, which is plenty enough to deliver onscreen explosions with scale and power, but when it comes to really deep bass throb and rumble it struggles to produce a musical low-down thump. The aforementioned Samsung HW-K850, for example, is far better at reproducing the full audio range but then, for Sky customers at least, it’s considerably pricier.

Likewise, although agile and well-balanced, there isn’t quite the high-frequency sparkle that you’ll get with more expensive speakers, which means music specifically can sound a little mild-mannered and lacking in atmospherics.

And the Soundbox is also only natively compatible with Dolby Digital Plus and not Dolby Atmos, (which is odd, considering Sky now broadcasts some Premier League football broadcasts with Atmos audio) or any form of DTS. Nevertheless, this should only be a problem if you’re only able to output a bit-streamed signal. When I tested with Blue Planet II and Star Wars VII - Force Awakens Blu-ray discs played through my Xbox One S, it processed the audio just fine.

Sky Soundbox review: Verdict

The Sky Soundbox is a peculiar product. Viewed from some angles, it doesn't make an awful lot of sense. It isn’t the most practical size or shape – owners may have to raise their TV or place the speaker on a lower shelf to accommodate it – and it’s far from the best TV speaker system you can buy for £799. At that price, this isn't a speaker I'd recommend.

On the other hand, if you're a Sky customer, it's a far more tempting proposition. For the discounted price of £299 or, even better, at £249 for Sky multiroom customers, it sounds utterly amazing and it’s a firm recommendation.