Bose SoundLink Flex Bluetooth speaker – more Bose goodness (review)

The Bose SoundLink Flex Bluetooth speaker is what you expect from Bose – great sound, beautifully made and comes in Black, White Smoke, Stone Blue and Carmine Red. Another surprise is the price – just $249.95 for a Bose quality product.

Bluetooth speakers are a ‘dime a dozen’, and the premium market is dominated by JBL, Sony, and Ultimate Ears. This is a direct competitor, although each has strengths and weaknesses.

Its strength is the elegant, highly durable powder-coated steel grille and a silicone exterior that won’t peel or flake and is resistant to rust corrosion and UV light. It is IP67 (1m for 230 minutes), can withstand typical drops, and even floats if you dunk it.

It is mono and has a main transducer (fancy word for single speaker) and dual-ported passive bass radiator giving it an exceptional frequency response, great volume and low distortion. New Bose tech – Position IQ technology optimises the sound regardless of the speaker orientation – hanging from its integrated loop, on its back or upright.

Finally, Bose claims 12 hours of use on a charge. We tested that – results later.

Bose SoundLink Flex Bluetooth speaker

WebsiteProduct Page and Manual
ColoursBlack, White Smoke, Stone Blue and Carmine Red
Country of originThailand
CompanyBose (Est 1964) by Amar Bose in 1964 in Framingham, Massachusetts. It is best known for its home audio systems and speakers, noise-cancelling headphones, professional audio products and automobile sound systems. Bose has a reputation for being particularly protective of its patents, trademarks, and brands and seldom reveals the specifications of its products. The majority owner is the Massachusetts Institute of Technology.
MoreCyberShack Bose news and reviews

We use Fail (below expectations), Pass (meets expectations) and Exceed (surpasses expectations or is the class leader) against many of the items below. We occasionally give a Pass ‘+’ rating to show it is good but does not quite make it to Exceed. Bose does not provide detailed specifications, so our review is based on best estimates.

First Impression – small, well-made, and quite heavy – Exceed

It is 201 x 90 x 52mm x .6kg. You can feel the quality with the soft-touch silicone exterior and the solid, powder-coated, perforated steel grille. There is a strong fabric hanging loop.

It naturally sits on its back, or you can gently balance it on its side. Controls are on the ‘top’ side – power, volume up/down, Bluetooth and a multi-function button.

There is a mic tucked in there somewhere, making it a hands-free speakerphone.

The Bose Connect App – not necessary but handy – Pass

Bose has ensured that you can do everything with a combination of the manual buttons, but the App makes it more accessible. It is fundamental and lacks an EQ or pre-sets, which would be nice to get the best from this speaker.

Battery – Pass

The twelve hours claim is based on playing music from Spotify’s Global Top 50 at 65% volume (comfortable indoor personal listening). We tested a 75% (comfortable outdoor personal listening) and got 7.5 hours.

Charge time of about 4 hours is dependent on the charger – you need at least 5V/1.5A/7.5W, or it can use any PD charger, which can reduce the time to around 3 hours.

Bluetooth 4.2 SBC– Pass

Our minor disappointment was the use of BT 4.2 (current version 5.2), which gives around a 10-metre line-of-sight range. We found that to be a stretch inside a typical home where walls etc., reduce that to about 6 metres. Latency is ok for lip-syncing to video.

It remembers the last eight pairing devices but is not multi-point (simultaneous connection to two host devices). In fact, you have to disconnect from the first host device to access the next.

Hands-free – Pass+

The volume is excellent, and mic sensitivity is far-field – suitable for a few metres. You can use it to invoke a voice assistant on your phone. But you must press the multi-function button to enable hands-free or answer a call, so it kind of defeats the purpose.

Party/Stereo/SimpleSync Mode – Pass

You can link two Bose Bluetooth speakers – SoundLink Flex, SoundLink Micro, SoundLink Color II, SoundLink Revolve (series I and II) and SoundLink Revolve+ (series I and II). It can create a stereo pair – this is best with an identical speaker (not tested).

Or you can connect it to a Bose SimpleSync sound bar (300/500/700/900) to act as a personal speaker – only one speaker.

SoundLink Flex PositionIQ – Pass

This is Bose’s first speaker with what amounts to a gyro that adjusts volume and tone depending on the speaker’s orientation. It is not a gimmick – but in our tests, we could not hear any significant difference in frequency response curves. The best sound stage came from the upright, horizontal position, and the worst came hanging on a hook.

How does it sound? Brilliant – Pass+

You have to remember that most IP67 sacrifice sound quality for water resistance. Bose has succeeded in making this small speaker produce a great sound.

It has mid-bass starting at 65Hz and growing strongly, then it flattens (good) right through to 7kHz, where it dips to avoid harshness, then back up for a strong finish 8-20kHz.

This neutral sound signature neither adds nor subtracts from the original music. The only issue here is garbage-in, garbage out – the better the music quality, the better it sounds. You can read more about How to tell if you have good music (sound signature is the key – guide).

It is a pleasure to listen to bass-heavy music (although don’t expect thumpy bass from a portable) and instrumentals. Being mono, there is no sound stage or directionality. I am curious what the stereo pair would sound like – they should be very good. But the Bose app does not have an EQ to recess bass, and using the standard SBC codec is more of a limiting factor.

The maximum volume is about 85dB, but there is some noticeable ‘compression’ at that level. Back off a few dB, and it is okay.

Good job, Bose, but how about an EQ?

CyberShack’s view – Bose SoundLink Flex is a great portable Bluetooth speaker

We have always liked Bose gear. Despite not publishing any ‘real’ performance specs, it manages to impress. But this speaker has an uncharacteristically lower price – perhaps Bose, like many premium brands, have decided it is better to get new users into the tent.

It has our unreserved buy recommendation if you are a Bose user.

You can see more at CyberShack TV S28:Ep3 Bose Soundlink Flex and Smart Soundbar 900


Its closest competitor is the $299 Sonos Roam – Is this the best BT/Wi-Fi portable speaker ever? (review) but it is a very different speaker with two amps/woofer/tweeter, Wi-Fi, BT, EQ, Qi Wireless charge and more. Buy Sonos if you want to use its multi-room audio features.

The JBL $199 Charge 5 (or Flip 6) has a very similar neutral sound signature to the Bose, with 20 hours of battery life. No downsides here.

Sony doesn’t have a direct competitor, but its $319 XE3000 portable has BT 5.2, dual speakers and dual passive radiators and up to 24 hours of battery life.

Ultimate ears are 360° sound speakers, and the $199 Boom 3 is the closest, with 15 hours of battery life, a better app/EQ and perhaps a tad more rugged.

Bose SoundLink Flex Bluetooth speaker








Ease of Use





  • Neutral sound signature
  • Bass is powerful for an IP67 speaker
  • Good far-field mic (no privacy mute)
  • Reasonable price


  • No app EQ
  • The older version of BT does not properly support multi-point connections
  • No Aux-in and USB-C is for charge-only (missed opportunity)

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