Short answer: the Xiaomi Sound Outdoor. It ranks #46 of 177 medium speakers by sound quality, rated 3.7/5, at $49.99; the Ultimate Ears Wonderboom 2 ranks #110, rated 2.9/5, and costs $80, so there is little reason to consider the other one.
The Xiaomi Sound Outdoor is the better-sounding option. An affordable waterproof outdoor speaker with a separate tweeter, decent battery life and linking to many more speakers. It links with other speakers (Speakersync, up to 100 speakers), which the Ultimate Ears Wonderboom 2 cannot. It charges over USB-C rather than Micro USB. Watch for: Bass reach is limited for the cabinet size, with a rated lower limit of 60Hz, and the boosted bass gets somewhat uncontrolled at high levels.
The Ultimate Ears Wonderboom 2 is the lighter choice. A small waterproof speaker that floats and is light enough to toss in a bag for the pool or beach. At 0.9 lbs (420 g) it weighs noticeably less than the Xiaomi Sound Outdoor at 1.3 lbs (597 g). The tradeoff: Not stereo, barely any bass, recessed treble.
Buy the Xiaomi Sound Outdoor. It is rated higher for sound quality than the Ultimate Ears Wonderboom 2 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Want more options? Browse the full Portable Bluetooth rankings.
An affordable waterproof outdoor speaker with a separate tweeter, decent battery life and linking to many more speakers.
A small waterproof speaker that floats and is light enough to toss in a bag for the pool or beach.
Prices on this page were last checked October 31, 2026 at 7:11 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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Specifications Side By Side
| Xiaomi Sound Outdoor | Ultimate Ears Wonderboom 2 | |
|---|---|---|
| Price | $49.99 | $80 |
| Ranked | #46 of 177 in Medium Size Portable Bluetooth Speakers | #110 of 177 in Medium Size Portable Bluetooth Speakers |
| App | No | No |
| Battery Life | 12 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| Built-in Microphone | Yes | No |
| EQ | No | No |
| IP Rating | IP67 | IP67 |
| Party Mode | Yes (Speakersync, up to 100 speakers) | No |
| Power Input | USB-C | Micro USB |
| Stereo | No | No |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 1.3 lbs (597 g) | 0.9 lbs (420 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.4 | 5.1 |
| Dimensions | 7.7” x 2.7” x 2.6” (196.6 x 68 x 66 mm) | 4.1” x 3.8” (104 x 95.3 mm) |
| Drivers | 20W woofer, 10W tweeter + 2x passive radiators | 2x 40mm active drivers + 2x passive radiators |
| Frequency Response | 60Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 30W | - |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) | SBC |
| Aux Input | No | No |
| Bass Extension (-10dB) | - | 82Hz |
| Maximum SPL | - | 88dB (measured by Alan Ross Reviews) |
| Strap | - | Yes (built-in loop) |
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