Our verdict, built on evidence: the Wonderboom 4 is a sequel that changes almost nothing and still earns its place, with TechRadar's 4/5 sound score, a 14-hour battery that testers beat, and an IP67 body that floats. The trade-offs are clear: no mic, no aux, no app, and sound that thins at high volume. It is a pool-bag speaker first.
— THE VERDICT · JUDGEANY EDITORSA familiar speaker with two new tricks
The Wonderboom 4 arrived on June 26, 2024, and anyone who owned the Wonderboom 3 will recognize it instantly. Ultimate Ears kept the same audio hardware, the same mug-sized cylinder, and the same big-button layout. SoundGuys, which tested the speaker for a week, puts it bluntly: besides a new USB-C charging port, the Wonderboom 4 has no hardware upgrades over the 3. What is actually new is the charging port and a Podcast EQ mode. This review compiles Ultimate Ears' official specifications, published expert reviews, and owner feedback. JudgeAny does not run a test lab: every measurement cited here belongs to the outlet that published it, and the score below is our editorial judgment based on that public evidence.
Sound: small speaker, outsized bass
The hardware is two 40 mm active drivers and two 46.1 x 65.2 mm passive radiators, arranged for 360-degree sound, with 8.5 W of output according to SoundGuys. Ultimate Ears' own spec sheet lists a maximum sound level of 86 dBC in normal mode and 87 dBC with Outdoor Boost. In practice, TechRadar gave Sound 4/5, praising punchy bass that does not overwhelm the mids and treble, plus separation that stands out for a portable speaker. T3 reached a similar place, calling the sound exemplary at normal volumes, with natural vocals and guitars, and only a slight graininess when pushed to the top of the volume range.
In a direct comparison with the Tribit Stormbox Mini, MyTechGear found the Wonderboom 4 slightly clearer in vocals and instruments, with bass that stayed present but controlled at higher volumes.
The catch shows up at high volume, and every serious review mentions it. SoundGuys found that past about 60% volume on a phone, the DSP trims bass to prevent distortion, and vocals and snare drums turn harsh in the upper mids. TechRadar agrees that detail falls away as the volume climbs, though it was impressed by how well the speaker handled complex tracks even when loud. None of this changes the overall judgment: at the volumes most people actually use, a speaker this size has no business sounding this full. It is not a party speaker, and buyers who want room-shaking bass should look at something larger.
The two EQ modes divide reviewers
The Wonderboom 4 has three sound settings, cycled with the tree-marked button underneath: standard, Outdoor Boost, and the new Podcast mode. Outdoor Boost is meant for open air, where bass disappears. It works by cutting bass and boosting treble, which helps sound carry, but TechRadar notes a clear loss in quality, and SoundGuys is blunter, calling the mode somewhat effective but not really pleasant-sounding. Podcast mode tunes the EQ toward vocal clarity. TechRadar heard a real difference in the kitchen, with words carrying more clearly, but added that only a keen-eared podcast fan would value it as a dedicated feature.
The published record splits on those modes. Tom's Guide, in its verdict, called the sound modes almost entirely unusable, and What's The Best listed both Outdoor mode and Podcast mode among the speaker's cons. The modes are a bonus, not a reason to buy. If you mostly listen to music at normal volume, the standard tuning is the one reviewers praise, and the modes change little about that.
Built for the pool, the beach, and the backpack
At 420 g and 104 x 95.3 x 95.3 mm, the Wonderboom 4 is roughly the size of a coffee mug, and TechRadar gave Design 5/5. The IP67 rating means it is sealed against dust and can be submerged in up to a meter of water for 30 minutes, and it floats, so a dunk in the pool is an anecdote rather than a repair bill. Ultimate Ears also rates it for drops from 5 feet, and TechRadar notes the same 1.5 m drop-proofing. The fabric wrap and rubberized bumpers top and bottom complete a design that is clearly meant to be tossed in a bag: a fabric loop on top takes a carabiner, though SoundGuys notes the carabiner itself is sold separately, unlike with the larger Everboom.
Four colors are available: Active Black, Cobalt Blue, Hyper Pink, and Joyous Bright, each with the trademark oversized volume buttons in a contrasting color. One genuine annoyance survives from earlier generations: the top buttons are unmarked for minimalism, and TechRadar warns it takes a little time to learn which one does what. Coverage of the Amazon listing puts the owner rating at 4.4 out of 5, with praise for balanced sound, portable size, and rugged build, according to Ultimate Pocket.
Battery and connectivity: long-lived, deliberately simple
Ultimate Ears claims up to 14 hours of playtime, with a 2.6-hour charge time using a BC1.2-compliant adapter, per its spec sheet. Published experience backs the claim: TechRadar routinely got better than 14 hours during testing, and What's The Best used the speaker regularly for a week, including for films and TV, without ever running it flat. Bluetooth is version 5.2 with a claimed 40-meter range, and SoundGuys notes the codec support is SBC only, with no higher-bitrate option. Multipoint is supported, so two people can take turns as DJ, and two Wonderbooms can be paired for stereo or double-up playback.
The sources disagree on one point: stereo pairing with the Wonderboom 3. TechRadar and T3 both say a Wonderboom 4 pairs with a Wonderboom 3 for stereo, while SoundGuys' FAQ states that stereo requires an identical speaker. Ultimate Ears' own page says the speaker does not connect with the Wonderboom 1, 2, BOOM, MEGABOOM, or HYPERBOOM, which leaves the Wonderboom 3 conspicuously off the exclusion list, siding with TechRadar and T3. If stereo pairing with an older unit matters to you, check the current guidance on Ultimate Ears' support pages before buying a second speaker.
What it leaves out, and who should skip it
The Wonderboom 4 has no microphone, so it cannot take calls, no aux input, so Bluetooth is the only way in, and no app support: the UE Boom app still does not recognize it, a gap SoundGuys calls disappointing. That simplicity is the point for some buyers and a dealbreaker for others. SoundGuys suggests the JBL Clip 5 as a cheaper alternative with app EQ and a built-in carabiner, though it is a mono, single-direction speaker rather than a 360-degree one. And TechRadar's value warning stands: if you do not need USB-C charging or Podcast mode, the discounted Wonderboom 3 offers the identical listening experience for less. Check the current price on Amazon before deciding, since the gap between the two generations moves with discounts.