Short answer: the Soundcore Boom 3i. It ranks #31 of 179 medium speakers by sound quality (rated 4.0/5) at $118.99 and is still sold new; the EarFun Uboom Slim ranks #43 (rated 3.7/5) and is discontinued, so it is only an option used.
The Soundcore Boom 3i is the deeper-bass pick. A warm, punchy waterproof speaker that sounds great and is a strong value. Its bass reaches about 56Hz before falling 10dB, against 63Hz for the EarFun Uboom Slim. It supports AAC Bluetooth, which the EarFun Uboom Slim lacks. It has an adjustable EQ, which the EarFun Uboom Slim lacks. The tradeoff: Not quite as good as a JBL Charge 5, doesn’t go quite as loud or sound quite as balanced, but very very close.
The EarFun Uboom Slim is the lighter option. A slim, affordable waterproof stereo speaker with long battery life that doubles as a speakerphone. At 1.2 lbs (560 g) it weighs noticeably less than the Soundcore Boom 3i at 1.7 lbs (783 g). It keeps a wired aux input, which the Soundcore Boom 3i lacks. It plays in stereo from a single unit, unlike the Soundcore Boom 3i. Watch for: Not as deep bass as others.
Buy the Soundcore Boom 3i. It is rated higher for sound quality, and the EarFun Uboom Slim is discontinued, so it is only available used.
Want more options? Browse the full Portable Bluetooth rankings.
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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| Soundcore Boom 3i | EarFun Uboom Slim | |
|---|---|---|
| Price | $118.99 | $79 Discontinued |
| Ranked | #31 of 179 in Medium Size Portable Bluetooth Speakers | #43 of 179 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | No | Yes |
| Bass Extension (-10dB) | 56Hz | ~63Hz |
| Battery Life | 16 hours (Manufacturer specified) | 16 hours (Manufacturer specified) |
| EQ | Yes | No |
| IP Rating | IP68 | IPX7 |
| Party Mode | No | - |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | 5.2 |
| Dimensions | 8.3” x 3.3” x 3.1” (210 x 85 x 78.5 mm) | 2.6”H x 7.1”W x 2.6”D (65 x 180 x 65 mm) |
| Drivers | 94mm woofer + tweeter | 45mm speaker drivers |
| Weight | 1.7 lbs (783 g) | 1.2 lbs (560 g) |
| Amplifier Power | 50W | 20W |
| Bluetooth Codecs | SBC, AAC | SBC |
| Built-in Microphone | Yes | Yes |
| Digital Aux Input | No | No |
| Lights | Yes | - |
| Strap | Yes (detachable strap) | - |
Related Speaker Comparisons
How Soundcore Boom 3i compares with other leading options: