There are lots of small portable Bluetooth speakers, and for good reason: People like taking their music with them, wherever they go. Unfortunately, most small Bluetooth speakers sound small — tinny and lacking bass. But Ultimate Ears' $100 Wonderboom 2 is an exception. As the best Bluetooth speaker for its size, it's small enough to be easily portable and large enough to produce a big sound, the Wonderboom 2 offers an appealing combo of features for the price.
The Wonderboom looks a bit like a squished UE Megaboom 3 — it's a little wider (3.8 inches versus 3.4 inches for the Megaboom 3), but much shorter (4.1 inches versus 8.9 inches). The second-generation model is just a smidge bigger than the original Wonderboom. It weighs 0.9 pounds — that's almost twice as heavy as the JBL Clip — which means it's small, but not what we'd consider an ultraportable.
On top of the unit you'll find buttons for power and Bluetooth pairing, as well as a fabric loop you could use to hang the speaker or carry it. The Wonderboom 2 improves on the design on the original by including a center button on top that lets you control playback (the previous model had the same features, but it lacked an obvious button). Press it once to play or pause a track and twice to skip ahead. You can adjust the volume with the large + and - buttons on the side.
The microUSB port for charging is located on the bottom under a cover. The Wonderboom doesn't include an auxiliary port for wired connections.
The Wonderboom produces a surprisingly full sound for a small speaker, with good bass and treble. It offers a bit more bass than the first-generation model. It's one of the best- sounding portable speakers you'll find for $100; the JBL Flip bests it slightly in sound quality — mainly because the Flip is bigger, which allows it to produce a wider soundfield.
Listening to Lizzo's "Truth Hurts" on the Wonderboom 2, the bass had good resonance and depth and her vocals were clear and easy to hear. The unit had enough bass to vibrate my desk on Billie Eilish's "bad guy." The acoustic guitar on Wilco's "Love Is Everywhere" sounded crisp.
The Wonderboom has impressive power. If you press the Outdoor Boost button on the bottom, it cranks to almost 100 decibels, and even without that it goes to 94 decibels. But it gets distorted at max volume, and it sounded better at around 85 decibels, which is enough to be heard under most conditions.
The Wonderboom 2 has an IPX67 rating, meaning it can be submerged in 3 feet of water for up to 30 minutes. I put it in a sinkful of water for 5 minutes and it continued to play without issue. It is also dust resistant.
UE says the Wonderboom 2 will play for 13 hours on a full charge, an improvement over the last generation. After I listened for more than 6 hours, the Wonderboom still had plenty of juice left — more than half of its capacity.
Getting the battery status is harder than it should be, though. You have to press the volume buttons up and down at the same time, and the speaker will play a sound that corresponds to one of three levels: high, medium or low. I would have preferred a visual indicator, as many Bluetooth speakers have.
Wireless and Setup
The Wonderboom 2 paired quickly with my iPhone. It had strong signal strength, maintaining a connection even with several walls between it and my phone.
UE doesn't offer an app for the Wonderboom, which is disappointing since its Boom and Megaboom apps have always been among the best. That also means there's no way to adjust the sound.
You can pair two Wonderbooms together by holding the center button on top of each unit for 3 seconds. You can pair it with an original Wonderboom; unfortunately, you can't pair it with a Boom or Megaboom speaker.
If you're looking for a portable Bluetooth speaker that's small enough to easily tote around, and you want very good sound, the Wonderboom will meet most of your needs. It has good bass for a small speaker and rivals the JBL Flip for overall best sound in a $100 speaker.
You can find smaller and lighter speakers, such as the JBL Clip, but they won't sound as good. If you are willing to go bigger, the UE Boom 3 produces better sound — though it also costs more, with a list price of $150. The Wonderboom hits a sweet spot in price, size and sound quality for portable Bluetooth speakers. If you have an original Wonderboom, there's not enough improvements in the second generation to warrant an upgrade, though.