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Not quite the complete package, but the SoundLink Flex might just have what it takes to satisfy your priorities… 


  • Sonic scale and confidence to spare
  • Impressively hardy build and finish
  • Good battery life


  • Loses some composure at volume
  • ‘Only’ Bluetooth 4.2
  • No EQ adjustment

Key Features

  • SpeakerphoneBuilt-in microphone lets you take calls when connected to a phone
  • Bose Connect appPersonalise settings, pair multiple speakers, update firmware


The days when being a ‘big’ brand with a ‘big’ reputation was all that was required to dominate a particular section of the consumer electronics market are, happily, over.

So it doesn’t matter that profiles don’t come much higher than that of Bose. If the company’s latest portable Bluetooth speaker is going to make an impression, it’s going to have to do a bit more than just show up with a big ‘Bose’ logo on its face.

Admittedly, Bose has never struck me as a company happy to rest on its laurels. But when you consider just how many very decent portable Bluetooth speakers are available at this sort of money (Sonos, Sony, JBL and Ultimate Ears – to name just a few – all want to part you from your cash) it becomes obvious the SoundLink Flex has its work cut out. Does it have what it takes to turn your head? Or, even more importantly, your ears?


  • UKRRP: £149.95
  • USARRP: $149
  • EuropeRRP: €169

The Bose SoundLink Flex is on sale now, and in the UK you should expect to pay very nearly £150. Customers in the United States will be asked for around $149, while in Australia it’s priced up at AU$199 or something very like it.

As already mentioned, this pitches the Flex into quite a considerable scrap. As well as the increasingly ubiquitous Sonos Roam, this sort of money buys very agreeable alternatives from the likes of Ultimate Ears and JBL. This is no walk in the park for Bose, in other words, no matter how portable its speaker is.


  • IP67 water and dust resistance
  • Multiple orientations
  • Three finishes

If you want your Bluetooth speaker to be truly portable, then ‘design’ is a big part of the deal. Bose seems to understand this, happily, so the SoundLink Flex is a tidy 9 x 20 x 5cm and a flyweight 600g. Add in its robust, hard-wearing soft silicone finish with powder-coated steel grille (fitted so snugly the Flex has an IP67 rating against moisture or dust intrusion) and the Bose has ‘portability’ pretty much covered.

Bose SoundLink Flex speaker grille

Bose has fitted the SoundLink Flex with its ‘PositionIQ’ technology (which is ‘accelerometers’ to anyone who doesn’t work in the marketing department), so that it knows its orientation and can adjust its EQs accordingly. The chassis features little moulded feet to allow the Flex to stand in the ‘landscape’ position or lie flat on its back, while there’s a hefty fabric loop at one end to allow it to hang off a carabiner, a hook or what-have-you.

The Flex is yours in a choice of finishes. As well as the ‘stone’ blue of this review sample, ‘smoke’ white and plain old black are available.


  • Bluetooth 4.2
  • App, voice and physical controls
  • 12 hours of battery life

Bose plays its cards mighty close to its chest sometimes, and where certain aspects of the SoundLink Flex’s specification are concerned the company’s poker face is unwavering.

Yes, the battery is good for twelve hours of playback (as long as you’re circumspect with the volume level). Yes, the Flex will go from ‘flat’ to ‘full’ after a couple of hours attached to the mains via its USB-C input. But power? It’s a secret – as is the type of amplification the Flex uses, although I reckon Class D is a pretty safe bet. DAC details? None are forthcoming – and although Bluetooth 4.2 connectivity proves adequate when getting some high-ish resolution digital audio files on board, the DAC inside the Flex can’t deal natively with a full-fat 24bit/192kHz file and must downscale.

Bose SoundLink Flex Connect app

What’s certain is that there is a single full-range dynamic driver inside the Flex – although its size and the material from which it is made is unknown (by me, at least). There are also a couple of ‘racetrack’ passive radiators offering some low-frequency reinforcement – but as to their size, well… you’re way ahead of me, aren’t you?

All of these secret ingredients can be operated using Google Assistant or Siri voice control. There is a fairly brief suite of physical controls on the SoundLink Flex’s chassis, too – so ‘power on/off’, ‘Bluetooth pairing’, ‘play/pause’ and ‘skip forwards/backwards’ are all accessible at the press of a silicone-covered button. Or you may choose to use the Bose Connect app instead – it’s helpful where setting up a stereo pair, for example, is concerned, but doesn’t have any EQ adjustment. So the sound you get is the sound Bose had decided you should be given.

Sound quality

  • Dynamic sound of considerable scale
  • Can get flustered by higher volumes
  • Good rhythmic expression

In quite a few ways, though, that’s just fine. In quite a few ways, the Bose SoundLink Flex is as accomplished a performer as any other portable Bluetooth speaker at this sort of money.

Certainly it wants for little where out-and-scale is concerned. Bose’s claim for ‘room-filling sound’ may be a bit fanciful (unless you’re in a pretty small room) but the SoundLink Flex sounds far bigger and burlier than its dimensions might hint at.

There’s no denying the low frequencies could be more expressive, and they could definitely handle a little more light and shade where detail levels are concerned but, blimey, they’re ample. Want bass? Bose has you covered. And there’s quite startling dynamic headroom here, too. If your favourite music travels a distance from ‘quiet’ to ‘loud’ the Flex is more than happy to travel right along with it. And the rather colourless low frequencies don’t get in the way of the Bose being quite adept where management of rhythms and tempos is concerned.

Bose SoundLink Flex top panel

The midrange, though slightly estranged from the lowest frequencies, is much more successful when it comes to dishing the details. A CD-standard 16bit/44.1kHz file of Scott Walker’s Black Sheep Boy is delivered with plenty of character and nuance, giving the vocalist every chance to communicate and engage. The transition to the top of the frequency is achieved calmly, too – which is really just as it should be, given the midrange and high frequencies are delivered by the same driver.

The Flex’s top end is very agreeable when listened to at sensible volume – there’s bite and shine to treble sounds, but there’s plenty of substance to them too. Only if you’re tempted to wind the volume right up do the highest frequencies become problematic – some spikiness and hardness creeps in and only becomes more apparent the louder you want to listen. I’d imagine this sort of volume is only really appropriate for outdoor listening, mind you, where absolute fidelity generally takes a back seat to ‘being able to be heard’. 

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Should you buy it?

You like a big sound from your little speaker The Flex has dynamism, scale and low-frequency presence to spare

You think louder = better The Bose can get quite flustered at high volume

Final Thoughts

Just because a product’s ‘not perfect’ doesn’t mean it won’t be perfect for some. The Bose SoundLink Flex is hardwearing, hardworking and is built to last – which will be ideal for some consumers

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How we test

We test every wireless speaker we review thoroughly over an extended period of time. We use industry standard tests to compare features properly. We’ll always tell you what we find. We never, ever, accept money to review a product.

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Tested over a few weeks

Tested using using music streaming services and audio formats


Does the SoundLink Flex support Party Mode?

Yes it does. You can link two Bose Bluetooth speakers together through the Connect app, and other supported speakers include SoundLink Micro, SoundLink Color II, SoundLink Mini II, SoundLink Revolve (series I & II) and SoundLink Revolve+ (series I & II).

Full specs

IP rating
Battery Hours
Size (Dimensions)
Release Date
Model Number
Frequency Range
Speaker Type

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