Ultimate Ears WONDERBOOM 4 Review

The Ultimate Ears WONDERBOOM 4 is the latest version of the brand's pocket-sized, go-anywhere Bluetooth speaker, and it sharpens a proven formula with two overdue additions: a USB-C charging port and a dedicated Podcast mode. It keeps the familiar rounded shape, the 360-degree sound projection and the rugged, waterproof build that made its predecessors a warm-weather staple. Independent laboratory testing rates it a great little speaker for outdoor use — with the honest limits that come with its size and price.

The WONDERBOOM 4 is built for the outdoors. It is compact enough to clip to a bag or drop in a rucksack, and its rugged housing carries an IP67 rating for dust and water resistance along with genuine impact resistance, so a drop on the patio or a splash at the beach is no cause for panic. The test highlighted its 360-degree audio projection as a real practical advantage: because sound radiates evenly in all directions, you never have to think about where the speaker points or sits, which suits a picnic blanket or a kitchen worktop equally well. It comes in five colourways, from Cobalt Blue to Sand Beige, that all perform identically.

For a speaker this small, the WONDERBOOM 4 delivers a pleasing, even sound, and the test noted it plays a little brighter overall than the WONDERBOOM 3. The defining constraint is loudness: it is not a very loud speaker at maximum volume, and pushing it hard introduces noticeable compression that flattens the sound. The dedicated Outdoor mode helps here, adjusting the sound profile to cut through open-air surroundings where bass naturally disappears. It is a speaker best judged as a personal or small-group companion rather than a party centrepiece — for that, the larger JBL Boombox 4 from the same test is the step up.

This is a deliberately utilitarian speaker. The test flagged that there is no companion app, and therefore no custom equaliser, and even a skip-to-previous-track control is absent — you get simple, physical playback buttons and little else. What you do get is dependable endurance: 13 hours of battery life on a charge, enough to soundtrack a full day out, now topped up over a modern USB-C connection. The new Podcast mode joins the returning Outdoor preset to lift spoken-word clarity. Two WONDERBOOM units, including a mix of the 3 and 4, can also be paired in stereo or Party mode for a bigger sound.

Against its own predecessor, the WONDERBOOM 4 is more a subtle refresh than a reinvention — the Podcast mode, USB-C port and slightly brighter tuning are the main changes, so WONDERBOOM 3 owners have little reason to rush. Shoppers wanting maximum portability with an integrated hook might prefer a smaller clip-style speaker, while those after app control and a fuller sound should look at the pricier picks in our best Bluetooth speakers guide, where the WONDERBOOM 4 is our budget recommendation. Design-led alternatives like the Marshall Emberton III and grab-and-go rivals such as the JBL Flip 7 are worth weighing too.

The Ultimate Ears WONDERBOOM 4 does exactly what it promises: a tough, waterproof, genuinely portable speaker that sounds good in the places phones and pricier speakers fear to go. Its 360-degree projection, all-day battery and rugged build make it an easy recommendation for the beach, the shower or the trail, and the move to USB-C is welcome. The trade-offs — no app or custom EQ, and compression when pushed loud — are exactly what you would expect at this size and price. As an affordable, knockabout speaker for life outdoors, it remains one of the best.

This review is based on independent laboratory testing rather than our own hands-on trial.