SoundLink Flex vs. Sonos Roam vs. UE Boom 3

In a discussion of portable speakers, Bose, Sonos, and Ultimate Ears (UE) are brands that will always come up. All three companies have a wide range of quality speakers in various sizes and prices.

In the sub-$200 price range, Bose SoundLink Flex, Sonos Roam, and UE Boom 3 are best-sellers for a reason.

Sonos Roam has the highest MSRP of the bunch, and nothing about the design or sound stands out above the other two speakers. However, it is WiFi-enabled and AirPlay 2 compatible, and it comes with Sonos’ best-in-class software. If you need the Apple compatibility, or if your house is already immersed in the Sonos ecosystem, the Roam is a solid purchase.

UE Boom 3 is usually available at the cheapest price of the three. It has an excellent design, customizable equalizer, 15 hour battery life rating, and plays in stereo rather than mono. It is a great value even at MSRP, but if you can find it on sale (which is occasionally possible) it becomes a no-brainer purchase decision.

Bose SoundLink Flex is the newest product on the list. It retails for the same price as UE Boom 3, but it will be harder to find the Bose on sale since it is only a few months old at the time of publish. Although SoundLink Flex has a bland design and lacks an equalizer, the sound quality is exceptional and many people consider this one of the top sub-$200 speakers on the market.

~~~ Check Price: SoundLink Flex ~~~

~~~ Check Price: Sonos Roam ~~~

~~~ Check Price: UE Boom 3 ~~~


To my ear, the Bose SoundLink Flex sound quality outperforms that of the Sonos Roam and UE Boom 3.

SoundLink Flex gets louder than the other speakers and stays crisp even at high volumes. There is no equalizer, but the sound profile is nicely balanced right out of the box.

Tech reviewers with a more acute ear than mine have commented that the soundstage is wider on the Roam and Boom 3, but I didn’t notice much of a difference.

Speakers with a more rounded design (like the UE Boom 3) tend to score high marks for soundstage, and I wonder whether or not this creates a bias for tech reviewers. Looking at the speakers, the UE Boom (with its rounded design) appears like it should have a wider sound width than the SoundLink Flex (with its rectangular design and forward-facing speakers only). But again, I couldn’t hear much difference.

Although Sonos Roam lags slightly behind SoundLink Flex in terms of sound quality, it still outperforms the Boom. And that isn’t to say that the Boom 3 scores poorly, either.

Another bonus with Roam and Boom 3 is that both speakers have a great companion app that features a customizable equalizer. SoundLink Flex lacks the EQ, even though it sounds great without customization.

The bottom line is that all three of these speakers sound good considering the sub-$200 price tag. SoundLink Flex has the signature Bose sound profile with great clarity throughout mid- and high-ranges, while Roam and Boom both have impressive bass and volume for the size.

Sound winner: Bose SoundLink Flex (although all 3 are good for a sub-$200 portable)


From a cosmetic standpoint, UE Boom is hard to beat. The simple cylindrical design is executed to perfection, with oversized buttons creating an attention-grabbing visual effect. The tight-wrapped fabric exterior gives the device a premium feel and appearance.

[UE Boom 3]

Sonos Roam is well designed, also, it just lacks the visual interest of UE Boom 3. The plastic construction looks cheap by comparison, and the only real design feature is a simple white “Sonos” logo.

[Sonos Roam]

Bose SoundLink Flex has the least impressive design, cosmetically, and kind of looks like a fanny pack.

[Bose SoundLink Flex]

In terms of design function, it all comes down to personal preference.

Roam is much smaller and lighter than the other options. It can be positioned vertically or horizontally, but it lacks a hook or hanger of any kind.

On the other hand, SoundLink Flex has a “utility loop” on one end that allows it to be hung from a clip, but it can only stand horizontally.

Boom 3 is probably the best of both worlds, with a cylindrical design that allows it to be stood vertically, while also having a bungee hanger for clipping or hanging the speaker.

Boom is definitely larger than Roam, and about the same size as SoundLink Flex. However, the SoundLink Flex feels bigger due to the awkward rectangular design, as opposed to the smooth and easy-to-grip cylindrical design of Boom.

None of these three speakers have a 3.5 mm aux jack. Whether you agree with it or not, this is the direction that portable speaker manufacturers are taking.

UE Boom 3 uses a Magic Button that can pause, play, and skip songs. It takes a little time to get accustomed to, but it is a nice feature to have once you learn to use it.

Controls on SoundLink Flex function well but are basic and unspectacular.

SoundLink Flex uses Bluetooth 4.2. Sonos Roam uses the newer Bluetooth 5.0 and also works with Apple AirPlay 2. UE doesn’t disclose which version of bluetooth the Boom 3 uses. Regardless, all three devices function well for bluetooth connectivity.

Design winner: UE Boom 3


To begin, all three speakers are IP67 rated. This means they can be submerged in three feet of water for up to 30 minutes and are also dustproof.

We didn’t test any of the speakers for drop-proofing or shock-proofing. And none of the products discussed here are rated for this. However, all three manufacturers claim that their speakers are drop-proof.

Boom 3 has exceptional build quality throughout. It has rubber ends (top and bottom), and the tight fabric wrapping won’t rip easily.

Sonos is also well-built, with silicone end-caps and solid plastic construction.

SoundLink Flex is solidly built with a metal grill which feels high-end. The body is easy to grip and feels sturdy.

Though we didn’t test the durability to any significant degree, all of these speakers should hold up well to wear and tear. The waterproof rating makes us feel comfortable with their durability, as do the Bose, Sonos, and UE brands.

Durability winner: Tie


UE Boom is listed at 15 hours of battery life, while Bose SoundLink Flex is listed at 12 hours, and Sonos Roam is rated for 10 hours.

In testing, these numbers seemed way off.

SoundLink Flex lasted about 8 hours at normal listening volumes (70-80%). Boom 3 only got 5-6 hours at the same volumes. And Roam lasted about 4-5 hours.

Having said that, other tech reviewers have found that the Boom lasts for 12+ hours. I don’t know if the firmware updates cause the battery to drain faster, or if I tested a faulty device.

If battery life is tremendously important to you, I would read some more reviews from other reputable tech sites before ordering. It is baffling to me that our testing for the Boom was so different from what other reviewers have found.

Sonos and Bose both charge via USB-C, while UE has a micro USB. To me, this isn’t a huge difference, and it wouldn’t sway my purchase decision. But micro USB ports are certainly more failure-prone, so this is a definite knock against the Boom 3, even if it isn’t a deal-breaker.

Unlike the JBL Charge series or Soundcore Motion Boom, none of these speakers functions as a power bank. So you can’t use the speaker to charge a phone or other device. Since none of these options have excellent battery life, it might be for the best that they aren’t power banks (since this feature drains the battery quicker).

Power winner: SoundLink Flex (tests better) & UE Boom 3 (rated for longer)


Sonos Roam is the clear winner for software, although all three options rate pretty well.

Roam is WiFi-enabled, so you can use the speaker with Alexa or Google Assistant (rather than having to connect to your phone for a voice assistant). It is also compatible with AirPlay 2, which gives anyone in the Apple ecosystem a way of playing audio without bluetooth.

Sonos has an excellent app with a customizable EQ, and also features Bluetooth 5.0.

Another great feature on the Roam is automatic TruePlay, which allows the speaker to adjust its audio based on the room environment. This is similar to the PositionIQ seen on SoundLink Flex.

To an extent, I feel like these features are “marketing speak.” The speakers can adjust sound slightly based on their orientation, but I am not aware of any detection system that would allow the speaker to “read” the room or modify output based on its surroundings. Nonetheless, the speakers do test well in any orientation, so we can’t totally discredit either TruePlay or PositionIQ.

Bose is an industry leader with their speaker technology, and Sonos is so advanced with smart speakers that other companies are shamelessly stealing their technologies. So, if anyone can make a futuristic-sounding feature like this work on a sub-$200 speaker, it would probably be Bose or Sonos.

UE Boom 3 has a well-designed app, also, which provides a customizable EQ and some extras. UE doesn’t disclose which version of bluetooth the speaker uses, but I would assume it is Bluetooth 4.2. Regardless, the function is solid.

The Bose Connect app is reliable but doesn’t provide many extras. For example, there is no adjustable EQ, so you are stuck with the stock sound profile. It is also strange that the speaker has Bluetooth 4.2, which was dated by the time the speaker was released in Fall 2021.

Software winner: Sonos Roam (although all 3 are good)

Final Thoughts

Sonos Roam is the most expensive even though it doesn’t sound or look any better than the others. But it is WiFi-enabled, AirPlay 2 compatible, and has excellent software and connectivity. So it still makes sense to purchase the Roam if your primary concern is “smarts” or integration with an existing Sonos system.

Bose SoundLink Flex is a new release, so it will be challenging to find it on sale. The design isn’t anything special, but I was extremely impressed by the sound quality. Many other tech reviewers agree that this is perhaps the best new portable speaker of 2021. If you are looking for a good value, great sound, and plug-and-play functionality, SoundLink Flex is a wise choice.

UE Boom 3 is usually available at the cheapest price of the three. It isn’t brand new, but it has a beautiful design, great software with an equalizer, and can play sound in stereo rather than down-mixing to mono sound. When it goes on sale, the value of this speaker is hard to beat.