These are not really the same size class, and that is the honest framing here. The Bose Soundlink Micro 2 ranks #18 of 62 small speakers by sound quality at $129; the Ultimate Ears Boom 4 ranks #113 of 179 medium speakers by sound quality at $114.99.
The Bose Soundlink Micro 2 is the lighter option. A waterproof mini speaker with a fabric strap for bags and bikes and USB-C charging. At 0.7 lbs (329 g) it weighs much less than the Ultimate Ears Boom 4 at 1.4 lbs (620 g). It supports aptX Bluetooth, which the Ultimate Ears Boom 4 lacks. The catch: Lack of clarity.
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 plays in stereo from a single unit, unlike the Bose Soundlink Micro 2. The tradeoff: Not much improvement over the old ones.
Buy the Bose Soundlink Micro 2 at $129 for a small speaker, or the Ultimate Ears Boom 4 at $114.99 for a medium speaker instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Prices on this page were last checked November 7, 2026 at 7:34 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
| Bose Soundlink Micro 2 | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $129.00 | $114.99 |
| Ranked | #18 of 62 in Small Size Portable Bluetooth Speakers | #113 of 179 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Battery Life | 12 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Built-in Microphone | No | No |
| EQ | Yes | Yes (via app) |
| IP Rating | IP67 | IP67 |
| Party Mode | Yes (Bose Party mode) | - |
| Power Bank | No | No |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | Pointing up | No |
| TWS | Yes | Yes |
| Weight | 0.7 lbs (329 g) | 1.4 lbs (620 g) |
| Aux Input | No | No |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | AAC, aptX, SBC | SBC |
| Bluetooth Version | 5.4 | 5.1 |
| Dimensions | 4.1” x 4.1” x 1.7” (104 x 104 x 43 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Charging Time | 3 hours | - |
| Drivers | 40mm full-range driver with passive radiator | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| Digital Aux Input | No | No |
| Strap | Yes (built-in strap) | Yes (built-in loop) |
| Maximum SPL | - | 85dBC (Manufacturer specified) |
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