Short answer: the Ultimate Ears Boom 4, though neither ranks well in its class. It ranks #103 of 157 medium speakers by sound quality (rated 2.9/5); the Boat Stone 350 ranks #135 (rated 2.3/5). Both are rated below 3.0/5 among the 157 medium speakers, and the Earfun Uboom L, ranked #1 at $49.79, is a better place to start if sound quality matters.
The Ultimate Ears Boom 4 is the better-sounding, longer-running pick. IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. It is rated for 15 hours of battery against 6 for the Boat Stone 350. The tradeoff: Not much improvement over the old ones.
The Boat Stone 350 is the lighter pick. 10W cylindrical stereo speaker with dual passive radiators, IPX7 water resistance, microSD card slot, and 3.5mm aux input. At 0.9 lbs (426 g) it weighs noticeably less than the Ultimate Ears Boom 4 at 1.4 lbs (620 g). It keeps a wired aux input, which the Ultimate Ears Boom 4 lacks. The catch: Midrange peaks with rolled-off treble.
Buy the Ultimate Ears Boom 4. It is rated higher for sound quality than the Boat Stone 350.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Ultimate Ears Boom 4 | Boat Stone 350 | |
|---|---|---|
| Price | $149.99 | - |
| Ranked | #103 of 157 in Medium Size Portable Bluetooth Speakers | #135 of 157 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Battery Life | 15 hours (Manufacturer specified) | 6 hours (Manufacturer specified) |
| IP Rating | IP67 | IPX7 |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Weight | 1.4 lbs (620 g) | 0.9 lbs (426 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.1 | 5.0 |
| Dimensions | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) | 3.5” x 7.1” (90 x 180 mm) |
| Drivers | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators | 2x 20mm tweeters + 2x 45mm drivers |
| TWS | Yes | Yes |
| EQ | Yes (via app) | Yes (multiple modes) |
| Built-in Microphone | No | Yes |
| Power Bank | No | - |
| Aux Input | No | Yes |
| Maximum SPL | 85dBC (Manufacturer specified) | - |
| Digital Aux Input | No | No |
| Bluetooth Codecs | SBC | SBC (inferred; additional codecs unverified) |
| Strap | Yes (built-in loop) | No |
| Bass Extension (-10dB) | - | 87Hz |
| MicroSD Playback | - | Yes |
| Amplifier Power | - | 10W |
Related Speaker Comparisons
More worthwhile head-to-heads for Ultimate Ears Boom 4:
- Ultimate Ears Boom 4 vs Earfun Uboom L
- Soundcore Motion 300 vs Ultimate Ears Boom 4
- Soundcore Motion+ vs Ultimate Ears Boom 4
- Soundcore Boost “upgraded” 2021 vs Ultimate Ears Boom 4
- Ultimate Ears Boom 4 vs Minirig 4
Prices on this page were last checked October 2, 2026 at 10:18 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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The Two Speakers In Full
Ultimate Ears Boom 4: $149.99 Amazon eBay
Older model: the Ultimate Ears Boom 3 (ranked lower, rated 2.9/5).
Pros: IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. 15 hour battery. Customizable EQ and speaker-pairing via the UE app.
Cons: Not much improvement over the old ones. Weak bass extension and thuddy bass. Gets distorted above 90%
Full Ultimate Ears Boom 4 review and specifications →
| App | Yes |
|---|---|
| Aux Input | No |
| Battery Life | 15 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC |
| Bluetooth Version | 5.1 |
| Built-in Microphone | No |
| Digital Aux Input | No |
| Dimensions | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Drivers | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| EQ | Yes (via app) |
| IP Rating | IP67 |
| Maximum SPL | 85dBC (Manufacturer specified) |
| Omnidirectional | No |
| Power Bank | No |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | Yes (built-in loop) |
| TWS | Yes |
| Weight | 1.4 lbs (620 g) |
- Links
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
- Ultimate Ears Boom 4 vs Ultimate Ears Boom 3
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom
- Ultimate Ears Boom 4 vs Klipsch Groove
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 2
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 3
- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 4
- Ultimate Ears Boom 4 vs DBSONO X-Blast F37
- Ultimate Ears Boom 4 vs Sony SRS-XE300
- See all 133 comparisons
Boat Stone 350 eBay
Pros: 10W cylindrical stereo speaker with dual passive radiators, IPX7 water resistance, microSD card slot, and 3.5mm aux input. Measured bass extension of 87Hz (-10dB).
Cons: Midrange peaks with rolled-off treble. Bass extension limited below 87Hz.
Full Boat Stone 350 review and specifications →
| Amplifier Power | 10W |
|---|---|
| App | No |
| Aux Input | Yes |
| Bass Extension (-10dB) | 87Hz |
| Battery Life | 6 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.0 |
| Built-in Microphone | Yes |
| Digital Aux Input | No |
| Dimensions | 3.5” x 7.1” (90 x 180 mm) |
| Drivers | 2x 20mm tweeters + 2x 45mm drivers |
| EQ | Yes (multiple modes) |
| IP Rating | IPX7 |
| MicroSD Playback | Yes |
| Omnidirectional | No |
| Power Input | USB-C |
| Stereo | Yes |
| Strap | No |
| TWS | Yes |
| Weight | 0.9 lbs (426 g) |
- Links
- Reviews, Comparisons and Sound Samples
- No independent measurement review is linked for this model; it is ranked from hands-on listening and comparison against similarly priced speakers.
- Head-to-Head Comparisons
- Boat Stone 350 vs Boat Stone 352
- Boat Stone 350 vs Doss Soundbox Pro
- Boat Stone 350 vs Marshall Emberton II
- Boat Stone 350 vs Marshall Emberton III
- Boat Stone 350 vs Ultimate Ears Wonderboom 4
- Boat Stone 350 vs Soundcore 2
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- See all 29 comparisons