Ultimate Ears WONDERBOOM 4
It Floats And It Bounces
Two specifications define this speaker and both are unusual. It is buoyant, so dropped in a pool or a lake it floats face-up and keeps playing, and it is built to survive being dropped onto hard ground.
Those matter because they address how small speakers actually die. A speaker taken to a poolside, a beach, a campsite or a bathroom gets dropped and gets wet, and most portable speakers tolerate one of those rather than both.
The spherical shape is part of that robustness — there are no corners to land on and no flat panels to crack — and it also projects sound reasonably in every direction rather than having a front.
Louder Than It Looks
It is genuinely small, comfortably held in one hand, and it plays considerably louder than that size suggests. For a bathroom, a small kitchen or a picnic blanket it is entirely sufficient.
Physics still applies. Bass extension is limited by the enclosure, so low frequencies are present rather than deep, and at maximum volume the tuning tightens up rather than distorting badly, which is a sensible design choice.
The omnidirectional dispersion also means it fills a small space more evenly than a directional speaker, which suits how it is actually used — placed on a surface in the middle of a room rather than aimed at a listener.
Simplicity Is Deliberate
There is no app requirement, no account, no Wi-Fi and no multi-room complexity. It pairs over Bluetooth and plays, with physical volume buttons on the body that you can find without looking.
For a speaker that lives in a bathroom or a bag, that simplicity is a genuine feature. There is nothing to configure, nothing to update and nothing that stops working when a service is discontinued.
Two can be paired together for stereo or louder playback, which is the only real feature beyond playing music, and it works without setup complexity.
Battery And Charging
Battery life is good for the size — enough for a full day of intermittent use — and it charges over USB-C on current versions, which matters because older versions used micro-USB and that was a genuine annoyance.
There is no power bank output and no aux input. It is a speaker rather than a hub, consistent with the rest of its design philosophy.
The hanging loop on top is more useful than it appears, since it can be hung from a shower rail, a tent pole or a bike, which is how a lot of people actually use it.
Against The Alternatives
Against larger portables like the Charge 5, this is far smaller and quieter with less battery, and it floats and fits anywhere.
Against a Sonos Roam, this is simpler, tougher and cheaper with no multi-room capability.
Against very cheap speakers, the build, the water and drop resistance and the volume for the size are all clear steps up.
The Verdict
The simplest genuinely good portable speaker: it floats, it survives being dropped, it plays far louder than its size suggests, and there is nothing to configure.
Bass is limited by physics, there is no aux input and no power output, and it will not fill a garden.
Buy it as the speaker you stop worrying about — the floating and drop resistance are why it survives where better-sounding speakers do not.
At a glance
Pros
- Floats face-up and keeps playing if dropped in water
- Built to survive being dropped on hard ground
- Considerably louder than its size suggests
- No app, account or configuration required
Cons
- Bass extension limited by the small enclosure
- No aux input and no power bank output
- Not loud enough to fill a garden or a party
- Omnidirectional dispersion means no stereo from one unit
Frequently asked questions
Does it really float?
Yes, face up and still playing. That matters because water is how small speakers usually die, and a speaker that survives being knocked into a pool is a genuinely different proposition from one that merely resists splashes.
Is it loud enough?
For a bathroom, a kitchen or a picnic blanket, comfortably — it plays much louder than its size suggests. For a garden party or open beach, no. A small enclosure cannot move enough air and nothing compensates for that.
Do I need an app?
No, and that is deliberate. It pairs over Bluetooth with physical buttons on the body, nothing to configure and nothing to stop working when a service is discontinued. For a speaker that lives in a bathroom, that simplicity is a feature.
Specifications
| Buoyancy | Floats face up |
| Drop resistance | Rated |
| Water rating | Yes |
| Dispersion | Omnidirectional |
| App required | No |
| Charging | USB-C on current versions |
| Stereo pairing | Two units |
| Hanging loop | Yes |
The bottom line
Floats, bounces, plays far louder than it looks, and needs no app. Limited bass and it will not fill a garden — the speaker you stop worrying about.
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