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 Boom 4 ranks #112, rated 2.9/5, and costs $114.99, so there is not much of a tradeoff to weigh.
The case for the Ultimate Ears Boom 4: A tough waterproof speaker that floats, with USB-C charging, app EQ and pairing with other UE speakers. It has an adjustable EQ, which the Xiaomi Sound Outdoor lacks. It plays in stereo from a single unit, unlike the Xiaomi Sound Outdoor. The catch: Not much improvement over the old ones.
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. 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.
Buy the Xiaomi Sound Outdoor. It is rated higher for sound quality than the Ultimate Ears Boom 4 and costs less, so only choose the other one for a particular feature it does better.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
A tough waterproof speaker that floats, with USB-C charging, app EQ and pairing with other UE speakers.
An affordable waterproof outdoor speaker with a separate tweeter, decent battery life and linking to many more speakers.
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
| Ultimate Ears Boom 4 | Xiaomi Sound Outdoor | |
|---|---|---|
| Price | $114.99 | $49.99 |
| Ranked | #112 of 177 in Medium Size Portable Bluetooth Speakers | #46 of 177 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Battery Life | 15 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| IP Rating | IP67 | IP67 |
| Power Input | USB-C | USB-C |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| Weight | 1.4 lbs (620 g) | 1.3 lbs (597 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.1 | 5.4 |
| Dimensions | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) | 7.7” x 2.7” x 2.6” (196.6 x 68 x 66 mm) |
| Drivers | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators | 20W woofer, 10W tweeter + 2x passive radiators |
| TWS | Yes | Yes |
| EQ | Yes (via app) | No |
| Built-in Microphone | No | Yes |
| Power Bank | No | - |
| Aux Input | No | No |
| Maximum SPL | 85dBC (Manufacturer specified) | - |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| Strap | Yes (built-in loop) | - |
| Party Mode | - | Yes (Speakersync, up to 100 speakers) |
| Frequency Response | - | 60Hz - 20kHz (Manufacturer specified) |
| Amplifier Power | - | 30W |
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