Clarity on the Ultra-Portable Bose Speakers: Choosing Between The Soundlink Micro vs Flex vs Revolve II

Bose has three worthwhile options at the smaller end of its classy Bluetooth speaker lineup. From smallest to largest, they are the Bose Soundlink Micro, the Bose Soundlink Flex, and the Bose Soundlink Revolve II.

These are the speakers to consider if you want something small enough to fit into a purse or small backpack that can offer much clearer and louder sound than you’ll get from your phone or laptop’s built-in speakers.

All three of these are excellent options; they offer Bose’s signature balance and careful, detailed delivery. As usual with Bluetooth speakers, the smaller options sacrifice a bit of soundstage, loudness, and bass performance, and the larger you go the more you get in these areas. We’ll describe those sonic differences as well as the feature differences in a nutshell below and then give our full takes and a roundup of what others have had to say.

Note that if you’re willing to carry a larger speaker (and spend a bit more) you may want to compare the Bose Soundlink Revolve II with its close big sibling the Soundlink Revolve+ II. And to go even a step up from that check out our coverage of the Bose Portable Home Speaker. Staying small, we have also compared the Bose Soundlink Micro with the Bose Soundlink Color II, an older offering that is still usually available.

Finally, if you’re willing to leave the Bose universe and want to hit the road with a speaker that’s durable, about the size of the Revolve II, and that delivers sweet, punchy, very loud sound, check out our travel speaker recommendation here.

Update History of This Article

This article was first published on March 4, 2022.

All three of these are excellent speakers. Here are their positive points in terms of features and how they contrast from each other:

  • Portability: Your first consideration will likely be how much speaker you’re willing to carry. The Bose Soundlink Micro is a just a bit bigger than the palm of a hand and at 0.64 lbs. / 0.29 kg doesn’t feel like much of a bother to add to a handbag or even coat pocket. The Bose Soundlink Flex is elongated to about twice the size and weight while still flat, and the Bose Soundlink Revolve II is just a bit bigger than that and cylindrical, like a tall can of soda.
  • Attachment/carry options: The Bose Soundlink Micro has a lovely flexible rubber strap on its back that makes it easy to attach to anything (a backpack or messenger bag strap, a canoe, a tent post, a scooter or bike handlebar…). The Flex has a carry loop and you may want to get a carabiner or (our favorite for travel) a HeroClip to hang it from things—but note that then of course it will swing and bounce around while in motion, which is not ideal. The Revolve II is more of a stationary option that you’re likely to place on a coffee or picnic table (in the middle of your space in order to take advantage of its 360-degree delivery).
  • Use near water: The Micro and Flex are completely IP67 waterproof and dustproof, meaning that they can survive under a meter of water for 30 minutes with no ill effect and don’t allow dust ingress. The Revolve II is IP55 dust and water resistant, meaning that you can expect it to survive the odd splash just fine, but you wouldn’t want to drop it in the bath or the pool. The Bose Soundlink Flex is the only one of the three that floats.
  • All three have some degree of rubberized coating to enable them to withstand shocks and drops.
  • The Micro, Flex, and Revolve II all have built-in microphones that allow you to use them as speakerphones to take calls and sound just fine to those on the other end of the calls. This feature is a rarity in current-generation Bluetooth speakers (perhaps because people don’t actually use it often).
  • The (included) charging cables for the Micro and Revolve II are micro-USB and for the Flex USB-C (the newer standard). Most people at this point have a mix of devices using both types of cables and this is not a particularly important issue for most of us.

Clean, Balanced, Detailed Sound

Starting with the smallest of the three, the Bose Soundlink Micro is a bit of a miracle for its size. It offers richness and a satisfying thump in the low end. It of course does not dive as low into the bass end as larger speakers, but placed on a solid surface there is a surprising amount of kick.

The Micro also goes plenty loud enough to be heard outside in somewhat noisy environments and, to the ears of many internet critics and consumer organizations, it is at or quite near the list of best-sounding tiny speakers. Its delivery remains clean and even at top volumes, with only to some ears a hint of loss of composure at the very loudest. There is some sense of separation of instruments though of course this is far from an immersive sound experience.

If you’re willing to go twice as big, the Bose Soundlink Flex is a better performer in all ways. The frequency response remains even but it dives deeper and can create a fuller impression of the bass end. As with the Micro this performance is even better when positioned flat on a resonant surface.

The Flex offers a sweet tone and clarity in the mids and highs and is able to fill a small room with sound fairly well. Unlike some Bluetooth speakers that overly boost certain frequencies (especially bass), critics across the web (all quite positive) say that the Flex delivers richness that is suitable for all genres, including classical and jazz music.

The Bose Soundlink Revolve II is not a lot larger than the Flex but has a different sonic objective. The cylinder is designed to be placed in the middle of a space (especially indoors, where it excels) and throw sound out evenly in all directions. While it won’t sound as great as a full on home stereo system, it’s a reasonable enough replacement for lush, even, detailed production that you can take and place in any room. The evenness of the frequency response is similar, there is again a nice level of detail, and a quite solid impression of bass is delivered particularly when placed on a resonant surface. I very much enjoyed this speaker and though not a lot of other critics have reviewed it, the sound is essentially the same as the old version of the Revolve, which I covered here.

The Negatives

As with other Bose speakers, there is one basic downside to the Bose Soundlink Micro, Flex, and Revolve II; they are on the pricey side. Yes, we think they’re worth it. But we also think given the lowered expectations for portable speakers most sets of ears are satisfied enough with some cheaper options that also sound pretty great.

The other small downsides to note with these ultraportable Bose speakers:

  • The Bose Soundlink Revolve II is merely water and dust resistant. Many other speakers at this size and price are now completely IP67 waterproof and dustproof, including the Bose Soundlink Micro and Flex that we discuss in this review and the alternative JBL Flip 6 mentioned just above.
  • The Bose Soundlink Micro has only six hours of battery life; opt for one of the larger options if you’re planning on being away from power for longer or else (as we recommend for travellers anyway) carry a good USB-C battery to recharge it.

Pricing is generally quite consistent but you can use the links below to check both Amazon in your country and the direct from Bose options.

Some reviewers and users complain that the black versions of these Bose speakers attract visible dust and lint. We find the Flex’s blue option to be particularly pleasing.

Bose Soundlink Micro
The best-sounding pocket-sized speaker we’ve heard and ultra-durable to boot
Bose Soundlink Flex
Twice as big, better overall detail and loudness, just as road-worthy
Bose Soundlink Revolve II
A better option for portable indoor use with gorgeous 360-degree sound

My personal favorite: The Flex. Fight it out with me in the comments if you dare.