Sonic Boom: Ultimate Ears Boom 4 Portable Bluetooth Speaker Review

As almost certainly one of the more reputable things to have happened on a Van Halen tour bus, the creation of the Ultimate Ears brand in 1995 has led to several iterations of its speakers. With a recent update to the Boom speaker range, Ultimate Ears (now owned by Logitech) has created a series of portable speakers that the brand promises deliver high quality sound in a durable package, perfect for parties and the great outdoors - including the Ultimate Ears Boom 4.

The Boom 4 is the second smallest and cheapest in the new lineup, with only the Wonderboom 4 below it in the hierarchy of Boom. This speaker is advertised as being “super-portable”, offering “balanced 360-degree sound”, “deep bass” and durability in the form of water, dust and drop resistance. Whether it would have survived the famous brown M&M rider is unclear.

With an RRP of £129.99, it’s slightly more expensive than the best budget Bluetooth speakers, which are typically available for under £100. But the higher price tag brings promise of rich acoustics, 15-hours of battery life, and the option to adjust your EQ to suit whatever you’re listening to. Does it live up to those promises? We asked Steven Shaw to face the music (dancing was optional).

Boom shake the room, or the sound of silence?

Typically, I find myself listening to music either through a pair of the best wireless earbuds when I’m out and about. Or, when I’m sat at my desk I’ll make use of a faithful Beats Pill Plus - a speaker originally released back in 2015. So, I was excited to hear the Boom 4 in action.

Set up was incredibly simple. A QR code on the quick start guide prompts you to download the UE app, and from there, pairing the speaker to your phone is about as painless as it gets. The app itself is very simple – one tab to control volume and use the speaker as a microphone, another to pair other UE speakers at the same time, and a third to set your preferred EQ mode (I’ll return to these later). From there, you’re ready to go.

Overall, I was impressed. Ultimate Ears claims that the Boom 4 provides “balanced sound with deep bass”. I would say this is mostly true. Given it is one of the cheaper and smaller portable speakers from Ultimate Ears, it was never going to be the richest acoustic experience on offer in the lineup. For that, you might want to consider something like the Ultimate Ears Everboom instead. That said, this speaker is no disappointment.

Sound was crisp and clear, and it was possible to pick out the detail in a lot of tracks that, in other speakers, might get drowned out by over-exuberant bass, for example. At quieter volumes, subtle parts of the music were still very clear.

It’s all about the bass

Having just praised the clarity of the speaker, there were times when I felt it was a little lacking in bass, particularly at lower volumes. When I was listening to music I have listened to regularly for years, it sometimes sounded thinner than normal. That’s not to say it sounded bad – but there was a discernible difference to how some songs usually sounded to my ears. Turning it up louder lets the bass come through a lot more, without distorting things too much. At higher volumes, it's a much richer experience.

Returning to the EQ settings, you can either tweak them yourself, or use one of five preset modes – Signature, Bass Boost, Cramped Spaces, Deep Relaxation, or Podcast/Vocal. There are clear differences in sound between these settings, although for me, Deep Relaxation made songs sound much bassier than the Bass Boost setting did. Bass Boost seemed to suppress anything in the Treble range a little more than I’d have liked, giving some songs a slightly muffled quality.

Even at full volume, I didn’t feel clarity was lost, which is impressive on such a small, inexpensive speaker. The sound travelled well, too. At mid-to-higher volumes, I did occasionally detect some distortion – Roger Daltrey hitting the high notes in Baba O’Riley caused a little bit of buzzing, for example. But in general, this wasn’t a big issue, even at full volume.

Microphone fiend

One final touch to highlight is the microphone button within the app. Pressing that allows you to speak into your phone, and the speaker projects your voice. With Bluetooth range of up to 45 metres, this is great if you're in another room or at the far end of the garden, and need to make an announcement. It's another clever detail that just gives the Boom 4 a little bit more functionality than some rival products.

Floating away in the bathtub

Ultimate Ears obviously pays attention to the design of its speakers, and the Boom 4 is no exception. It's designed to stand out – which for some will be a plus, for others, perhaps less so. Personally, I liked it. It’s quite tactile, using a combination of silicone and soft fabrics – it's a nice change from the metal mesh you often find on speakers.

There's also some effort to be environmentally conscious – a minimum of 52 per cent of the plastic components are recycled, while the external polyester fabric is 100 percent recycled. The 360-degree design means you can easily pop this in the middle of a coffee table, and everyone in the room will have a similar listening experience.

But it isn’t just designed for staying at home. Described as “the ultimate go-anywhere speaker”, it’s very light - just 620 grams - and there’s a small fabric loop so you could, for instance, strap it to your backpack as you head out for the day.

While it's also described as "virtually indestructible", I think the word "virtually" is perhaps doing some heavy lifting. But it feels durable, and more than capable as an outdoor speaker. It’s drop-proof, dust-proof and waterproof, with an IP67 rating that means it can withstand being in up to 1 metre of water for up to 30 minutes.

The charging port is protected by a silicone cover to give it that waterproofing. When I dropped it in the bath to test this, I noticed that as well as the speaker floating, it would roll, and the charging port stayed above the surface. As a piece of thoughtful design, this is particularly good.

Just as importantly, after it had its bath, and once it had dried out, I tried it again, and it worked just as well as it had done beforehand.

Don't stop me now

Battery life is also worth mentioning. Ultimate Ears claims the Boom 4 lasts for around 15 hours, when played at 30 per cent volume. I'm quite happy to play my music relatively quietly in the background. And battery wise, I was still listening to it after well over 20 hours of playback. Even then, the battery was still showing at 40 per cent. Of course, it won't last as long if you turn it up loud, but nevertheless, it's still very impressive battery performance.

Any downsides?

Honestly, for an affordable, portable Bluetooth speaker, there really isn't too much to complain about. I've highlighted how the bass can feel a little thin at low volumes, and how there can be a little bit of distortion at higher volumes. But overall, I felt the sound was excellent, especially for the price.

Would I, as the marketing photos suggest, be using it at a pool party, or outdoors next to a firepit? I don't think it would be the strongest performer in crowded places. But for a small group at the beach, or in your garden in the evening, it will do a very acceptable job. The ability to pair multiple Boom speakers together is a clever touch, which could certainly augment what this offers – although it does mean buying more speakers.

The design is likely to be polarising. Anyone who likes bold and brash may like this more than those who prefer muted and understated. Colours like cobalt blue, enchanting lilac and raspberry red aren't designed to blend in – although active black is a little more mellow.

Price and competition

At £129.99, this is a more premium device than many budget Bluetooth speakers that are often available for under £100. It undercuts the Sonos Roam 2 (RRP £179, but we've seen it on sale for £139). It's also cheaper than the 2024 version of the Beats Pill, which has an RRP of £149.99.

There's also the JBL Flip 6, with its RRP of £129, but sometimes on sale for under £90. The Flip 6 is arguably the most like the Boom 4 in terms of what it offers, and the JBL speaker has a slightly shorter battery life, but the same IP67 rating.

Overall, while the Boom 4 isn't an absolute bargain, it certainly isn't overpriced, either. If you buy this, I don't think you'd feel short-changed.

Who is it for?

Whether this speaker is for you or not will depend a lot on what you want from your music. If you want ear-splitting volume and incredible depth in the bass, then this probably won’t give you enough of either. But, if you just want to listen to music at your desk, in the background at a dinner party, or even outside with a small group of friends, this will do a great job for you.

As I mentioned before, this speaker simply isn't big enough to provide the richest, or loudest, soundscape for you to listen to. It still packs a punch, and it could be ideal for short camping trips, days out to the beach, or small parties in your back garden. Or, if you're looking for something you can carry round the house with you – maybe from your desk, to the kitchen while you make dinner, or to play something relaxing while you do some yoga in the lounge – its portability makes this a great choice.

Would we recommend it?

Ultimate Ears describe the Boom 4 as “bold and bassy”. In terms of design, it's certainly bold. Is it bassy? At louder volumes, the bass comes through well, but it's not quite so good (although still crisp and clear) if you prefer to listen to music more quietly. I also felt that the EQ settings that accentuate the bass ended up making the music sound a little strange. But I guess "bold and bassy-ish" isn't an especially pithy marketing pitch.

On the whole though, the Boom 4 gets a lot more right than wrong. The clarity is excellent, volume is punchy (topping out at 85 dB), and it doesn't get too distorted even at full blast. Is it going to match the best of the best? Of course not, but it isn't meant to. It's meant to be a great compact speaker that delivers superbly clear sound at an affordable price. And in that respect, it does an excellent job. Inevitably there are a few compromises, but this is a great little speaker, that I would definitely recommend.

More items to consider

Who tested it?

Steven Shaw, Senior Tech Writer and Reviewer at What's the Best, tested the Ultimate ears Boom 4 speaker.

Steven used the speaker over several weeks, comparing it with other devices, and seeing how it stacked up against those, and against the claims of the manufacturer.

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Steven Shaw is a Senior Tech Writer and Reviewer for What’s the Best. Steven writes how-to guides, explainers, reviews and best-of listicles covering a wide range of topics. He has several years of experience writing about fitness tech, mobile phones, and gaming.

When Steven isn’t writing, he’s probably testing a new smartwatch or fitness tracker, putting it through its paces with a variety of strength training, HIIT, or yoga. He also loves putting on a podcast and going for a long walk.

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