Expert's Rating
Pros
- Tiny
- Waterproof, dustproof, drop-proof
- Two can be linked into a stereo pair
Cons
- Thin, closed-in sound
- Wimpy bass
- Expensive for what’s delivered
Our Verdict
This tiny speaker is entirely unimpressive, with thin, closed-in sound and wimpy bass. It’s hardened against the elements, but that doesn’t make up for poor sound quality.
Best Prices Today: Ultimate Ears Wonderboom 2
Small, portable Bluetooth speakers are all the rage these days, and with good reason—they let you share your music with anyone, anytime, anywhere. And some are even waterproof, or at least water-resistant, so you can party next to the pool without worrying that water will dampen the mood by shorting out the speaker.
One interesting model is the Wonderboom 2 from Ultimate Ears. Heck, even the name in intriguing. This little pod promises big sound, so I had to check it out. Sadly, that promise is entirely unfulfilled.
This review is part of TechHive’s coverage of the best Bluetooth speakers, where you’ll find reviews of competing products, plus a buyer’s guide to the features you should consider when shopping.
Features
The roughly cylindrical Wonderboom 2 is small enough to fit in the palm of your hand, measuring a mere 4 inches tall and 3.75 inches in diameter and weighing less than 15 ounces. Most of the unit is covered with an athleisure-inspired, two-tone knit fabric in a variety of color options.
It purports to produce 360-degree sound using two 40mm active drivers and two 46x65mm passive radiators. Ultimate Ears does not disclose the amplifier power or the configuration of drivers and radiators. The frequency range is specified to extend from 75Hz to 20kHz with a maximum output level of 86 dBC; an Outdoor mode increases the maximum level to 87dBC.
Audio input is strictly via Bluetooth using the A2DP profile; there is no physical input at all. Up to two source devices can be connected simultaneously, and you can stream audio from either one at will. Even better, two Wonderboom 2s can be wirelessly linked together for true stereo sound.
A rechargeable lithium-ion battery provides up to 13 hours of playtime. Charging takes up to 2.6 hours using the micro-USB port behind a waterproof cover.

Oops. No worries! The Wonderboom 2 boasts an IP67 rating, which means it’s waterproof, as well as dustproof.
Speaking of waterproofing, the Wonderboom 2 carries an IP67 rating. That means it can survive being immersed up to 3.3 feet in fresh water for up to 30 minutes, and it’s protected from harmful effects of dust. (You can read more about IP codes in this story.) Ultimate Ears also claims it is “drop-proof,” having drop tested it from a height of five feet.
You can’t miss the volume up and down controls, which are large, brightly colored buttons shaped like “+” and “-“ on the side. Oddly, the “-“ looks like a minus sign only when the unit is lying on its side, in which case it can roll around. Still, I suppose it’s meaning is clear even when it’s upright.
On the top, the central button controls playback (play/pause/skip tracks) and lets you wirelessly connect two Wonderbooms into a stereo pair. The power light doubles as a battery-charging indicator as well as the power button itself. Also on the top is the Bluetooth pairing button and LED indicator. The only other control is a central button on the bottom that engages the Outdoor mode.
Performance
Ultimate Ears sent me two Wonderboom 2s, so I listened to one by itself and both wirelessly linked into a stereo pair placed about four feet apart in front of me, forming a roughly equilateral triangle with my head. For source material I used tracks from Tidal’s Master library from my iPhone XS via Bluetooth.
Starting with a single Wonderboom 2, I listened to “Gara” from the album Rough Guide to Zakir Hussain. The great tabla player is joined by a sitar on this album, but the Wonderboom 2 hardly does the instruments justice. The track sounded thin and closed in, like it was coming from within a box. Engaging Outdoor mode made it louder, but the sound of the tabla was still thin and sharp with no depth. Adding the other Wonderboom 2 in a stereo configuration made a decent soundstage, but it did nothing for the overall sound quality.
Next up was “Giant Steps” from Poncho Sanchez’ album Trane’s Delight, which features the conga legend with full big band. Again, a single Wonderboom 2 sounded thin and bright with very little bass. The stereo pair sounded better because of the wider soundstage, but no better in other respects. My notes on another jazz track, “Desafinado (Take 2)” from Art Pepper’s album Promises Kept, are no different.
For some classical music, I listened to the Game of Thrones Suite, a suite of themes from the HBO series as recorded by the Danish National Symphony Orchestra for the album Fantasymphony. Once again, the Wonderboom 2 sounded thin and bright, and the bass vocal soloist sounded congested with no real weight.
Hymn to the Virgin by Benjamin Britten is written for a cappella choir. I listened to a recording of this gorgeous piece by Schola Cantorum under the direction of Tone Bianca Sparre Dahl for an album of the same name. As expected by now, the Wonderboom 2 produced a thin, small sound.
I found one track that had noticeably better bass than I’d heard up to that point: “High Today” from The Saga of Wiz Khalifa featuring Logic. The overall sound was still thin and closed in, but the bass was surprisingly better than any other track I tried. This is the kind of music that most kids would listen to on the Wonderboom 2, not the world, jazz, and classical stuff I prefer. But how can it do better with one type of music than another? Strange….
Comparison with Tronsmart Element Force, Urban Ears Rålis, JBL Xtreme 2
I have several Bluetooth speakers on hand from previous reviews, so I listened to all the tracks on three others in addition to the Wonderboom 2: the Tronsmart Element Force ($53.99 on Amazon), Urban Ears Rålis ($199.99 on Amazon), and JBL Xtreme 2 ($249.99 on Amazon).
The Wonderboom 2 sells for about $100 each, so two of them are in the same price ballpark as the Rålis and Xtreme 2, while the Element Force is significantly less. The Tronsmart and JBL are both rated IPX7 waterproof (not dustproof), while the Urban Ears is not waterproof at all. Also, the Rålis and Xtreme 2 are larger and heavier than the Wonderboom 2, though both are designed for on-the-go listening. The Element Force is only slightly larger than the Wonderboom 2, and two of them can also be wirelessly linked into a stereo pair.
It was immediately apparent that all three speakers outperformed the Wonderboom 2. In every case, their sound quality was clearer, richer, fuller, and more open. Also, their bass was much better, which certainly isn’t surprising with the Rålis and Xtreme 2. As I noted in those reviews, their bass is a bit boomy, but I’ll take that over anemic bass any day. Even the little Element Force had better bass, though not as big as the other two.
Naturally, the one area in which the pair of Wonderboom 2s beat the others was stereo separation. The Rålis and Xtreme 2 have virtually no stereo separation, while the tiny Tronsmart never ceases to amaze me with its virtual stereo soundfield, but it’s not as wide as two physically separated speakers.
Bottom line
I am entirely unimpressed with the Ultimate Ears Wonderboom 2. It sounds thin and closed in, and its bass is anemic. Linking two into a stereo pair provides good stereo separation, but that does nothing to improve the overall sound quality.
Plus, at $100 each, it’s pretty expensive. I would definitely choose the Tronsmart Element Force over the Wonderboom 2—it sounds better, it’s not much larger, it’s also waterproof, and it’s half the price. If you’re willing to spend $200—the cost of two Wonderboom 2s—the Ultimate Ears Rålis sounds far better, though it is much larger and heavier, it’s not waterproof, and it doesn’t have any stereo separation. If you want something that sounds much better and is still waterproof, the JBL Xtreme 2 is the ticket, though that will set you back $250.