Ultimate Ears WONDERBOOM 4 Review: Rugged but Familiar

This Ultimate Ears WONDERBOOM 4 review looks at a small Bluetooth speaker built around one idea: music that fills a space from every direction, in a body that can take a soaking and a tumble. It is aimed at casual outdoor listeners who want something tough and simple for the pool, the beach or the backyard, rather than a feature-packed smart speaker. It sits in the mid-range part of the market.

This review is based on manufacturer specifications and what independent experts report, not on hands-on testing by us.

What the WONDERBOOM 4 is trying to be

The WONDERBOOM 4 is built around portability and durability. It has no app, and you pair it over Bluetooth 5.2, press play and leave it wherever suits you.

That simplicity is the appeal, and also the limit. Reviewers like what it does within its small size, but a common criticism is that it has no app, only two sound modes, no microphone and no aux-in. It is recommended in 8 expert buying guides, which suggests it is a safe choice for the kind of listener it targets. The two published expert scores are more measured, and we cover them below.

Ultimate Ears WONDERBOOM 4 review: design and build

The headline durability numbers are an IP67 rating for dust and water, and a drop test from 1.5 m (5 ft). IP67 means the speaker is sealed against dust and can handle immersion in water, and Ultimate Ears says it floats. For a speaker that will live near pools, in beach bags and on patio tables, that combination matters more than almost any sound spec. It means a splash, a spill or a fall in the shallow end isn't a disaster.

Size and weight are reasonable for something you will carry around. It stands 4.09 in (104 mm) tall, is 95.3 mm wide and weighs 14.81 oz (420 g).

There are four colour options: Active Black, Cobalt Blue, Hyper Pink and Joyous Bright. Ultimate Ears also says the plastic parts include at least 31% post-consumer recycled plastic, a small plus for buyers who care about materials. The speaker comes with a 2-Year Limited Hardware Warranty.

Features and what they mean day to day

360° sound

The defining feature is 360° sound from one small speaker. In practice this means you don't need to aim the speaker at your listeners. Put it in the middle of a table or beside a pool and people on every side hear roughly the same thing. Reviewers praise this consistency wherever the speaker is placed, and it is one of the main reasons to pick this model over a speaker that fires sound in one direction.

Under the hood are two 1.57 in (40 mm) active drivers and two passive radiators, each measuring 1.81 x 2.57 in (46.1 x 65.2 mm). Passive radiators help a small enclosure produce more bass than its size would suggest, and reviewers describe the sound as punchy and bassy for such a small speaker.

Sound modes

There are two EQ settings: Outdoor Boost and Podcast Mode. Outdoor Boost is one of the two EQ settings, and its maximum sound level is listed as 87 dBC. Podcast Mode is aimed at spoken-word content. That is the extent of the tuning. There is no app, so you can't adjust the sound beyond those two modes. A common criticism is that this feels limited, and if you like tweaking EQ you will find it restrictive.

Pairing and connectivity

The speaker can connect to 2 source devices at once. It can stay connected to two source devices at once. Google Fast Pair makes setup on Android phones quick. Wireless range is listed as 40 meters (131 feet).

The Double Up feature lets you pair two speakers for stereo. Reviewers count this among the speaker's strengths, since two small units can cover a larger space than one. It does mean buying a second speaker, so it is an optional upgrade, not something included.

What's missing

Two omissions come up repeatedly: there is no microphone, so it can't act as a speakerphone, and there is no aux-in. If you want to plug in a wired source or take calls through the speaker, this isn't the model for it.

Battery and charging

Ultimate Ears quotes up to 14 hours of battery life, charged over USB-C. That is enough for a full day outdoors and then some, and USB-C means you can use the same cable as your phone or laptop. Reviewers list the battery among the strengths. As with any battery claim, actual runtime depends on volume and how you use the speaker, so treat 14 hours as a best case.

Sound performance: what the specs and experts say

Maximum sound level is listed as 86 dBC in normal mode and 87 dBC in outdoor mode. Those figures are close together, which hints at the main limitation: this is not a party-volume speaker. Reviewers say it doesn't get very loud, and that it can distort and lose bass at higher volumes. In a quiet backyard or beside a pool that is workable. In a noisy space, or with a crowd, you may run out of headroom.

The experts who praise the sound do so in context: punchy and bassy for its size, with even coverage in all directions. It is best thought of as a casual listening speaker for background music and relaxed gatherings.

What experts like and what they criticise

Expert opinion is positive but not glowing. SoundGuys scores it 6.5/10 and Tom's Guide scores it 3.5/5, and it averages 6.8/10 across those 2 expert reviews. That is a respectable score for a rugged, simple speaker, not a standout.

What reviewers praise:

• Punchy, bassy sound for such a small speaker
• Consistent 360° sound wherever you place it
• A tough IP67 build that floats and survives 1.5 m drops
• Up to 14 hours of battery, charged over USB-C
• The option to pair two speakers for stereo with Double Up

What reviewers criticise:

• It is barely an upgrade over the WONDERBOOM 3
• It distorts and cuts bass at higher volumes, and doesn't get very loud
• There is no app, and only two sound modes
• There is no microphone and no aux-in

The point about the WONDERBOOM 3 matters for existing owners. If you already have that model, reviewers suggest there is little reason to move up.

Who should buy it, and who should skip it

Buy it if:

• You want a speaker for the pool, beach, backyard or campsite that you don't have to baby
• You value even 360° coverage over precise stereo imaging
• You like the idea of starting small and later adding a second speaker for stereo
• You prefer a simple speaker with no app to set up

Skip it if:

• You want loud, distortion-free volume for a crowd
• You want app-based EQ or more than two sound modes
• You need a speakerphone microphone or a wired aux input
• You already own the WONDERBOOM 3

How it fits among portable speakers

The portable Bluetooth speaker category is crowded, and most models trade off size, loudness, durability and features. The WONDERBOOM 4 leans toward durability, simplicity and all-round coverage, and gives up volume, controls and call support. If you are comparing options, our reviews of the JBL Go 4, the Anker Soundcore 2 and the Bose SoundLink Flex (2nd Gen) cover other portable speakers and are worth reading alongside this one.

Verdict

The WONDERBOOM 4 is easy to understand: a rugged, floating, easy-to-use speaker that spreads sound in every direction and runs for up to 14 hours. Those are the things that matter most for outdoor, water-adjacent use, and they are where it earns its recommendations. Its weaknesses are just as clear. It has limited volume, no app, only two sound modes, no mic and no aux-in, and it is a small step from the previous generation.

For casual listeners who want something durable and low-fuss, it is an easy speaker to live with. For anyone who wants more volume, more control or more features, it is worth looking at alternatives before you buy.

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