Short answer: the Sony ULT Field 3, if you are buying new. The Sony XB33 ranks higher than the Ultimate Ears Boom 4 (#77 vs #113 of 175 medium speakers) but is discontinued; its replacement, the Sony ULT Field 3, is rated 3.4/5 at $208 and is still sold new.
The Sony XB33 is the better-sounding, longer-running choice. IP67 rated and lightweight (2.4 lb). It is rated for 24 hours of battery against 15 for the Ultimate Ears Boom 4. It supports LDAC Bluetooth, which the Ultimate Ears Boom 4 lacks. The tradeoff: Not very loud.
The Ultimate Ears Boom 4 is the lighter option. IP67 rated, floats, and finally charges via USB-C instead of the older Booms’ Micro-USB. At 1.4 lbs (620 g) it weighs much less than the Sony XB33 at 2.4 lbs (1.1 kg). The tradeoff: Not much improvement over the old ones.
Buy the Sony ULT Field 3, the replacement for the discontinued Sony XB33; it is rated higher for sound quality than the Ultimate Ears Boom 4.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
Specifications Side By Side
| Sony XB33 | Ultimate Ears Boom 4 | |
|---|---|---|
| Price | $110 Discontinued | $129.99 |
| Ranked | #77 of 175 in Medium Size Portable Bluetooth Speakers | #113 of 175 in Medium Size Portable Bluetooth Speakers |
| App | Yes (Sony Music Connect App) | Yes |
| Aux Input | No | No |
| Bass Extension (-10dB) | 50Hz | - |
| Battery Life | 24 hours (Manufacturer specified) | 15 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC, LDAC | SBC |
| Bluetooth Latency | 110ms | - |
| EQ | Yes (3 band) | Yes (via app) |
| IP Rating | IP67 | IP67 |
| Maximum SPL | 97dB (measured by Alan Ross Reviews) | 85dBC (Manufacturer specified) |
| Party Mode | Yes (Party Connect up to 100 speakers) | - |
| Power Bank | Yes (USB-A) | No |
| Stereo | Yes | Yes |
| Omnidirectional | No | No |
| Weight | 2.4 lbs (1.1 kg) | 1.4 lbs (620 g) |
| Bluetooth Version | 5.0 | 5.1 |
| Dimensions | 9.7” x 3.8” x 4.2” (246 x 97 x 106 mm) | 7.2” x 2.9” x 2.9” (184 x 73 x 73 mm) |
| Amplifier Power | 16W RMS | - |
| Drivers | 2x 48x70mm X-Balanced racetrack drivers + 2x passive radiators | 2x 1.57” (40mm) active drivers + 2x 1.81” x 2.57” (46.1 x 65.2mm) passive radiators |
| Digital Aux Input | No | No |
| Lights | Yes | - |
| Power Input | USB-C | USB-C |
| TWS | Yes | Yes |
| Built-in Microphone | - | No |
| Strap | - | Yes (built-in loop) |
Related Speaker Comparisons
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- Soundcore Motion 300 vs Sony XB33
- Soundcore Motion+ vs Sony XB33
- Soundcore Boost “upgraded” 2021 vs Sony XB33
- JBL Charge 6 vs Sony XB33
- JBL Flip 6 vs Sony XB33
Prices on this page were last checked October 12, 2026 at 4:13 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
Sony XB33: $110 Discontinued eBay
Newer model: the Sony ULT Field 3, ranked higher, rated 3.4/5, released Apr 2025.
Older models: the Sony SRS-XB31 (ranked lower, rated 2.8/5) and the Sony SRS-XB30 (ranked lower, rated 2.6/5). See every Sony XB and ULT generation.
Pros: IP67 rated and lightweight (2.4 lb). App-controlled color LED lighting, Party Connect links up to 100 speakers. ~19 hour real-world battery without lights. Measured bass extension of 50Hz (-10dB).
Cons: Not very loud. Upper bass peaks, midrange dip, upper midrange peaks, not very neutral. Speaker will not remain at max volume and will turn itself down automatically. Discontinued.
Full Sony XB33 review and specifications →
| Released | May 2020 (6 years ago) |
|---|---|
| Amplifier Power | 16W RMS |
| App | Yes (Sony Music Connect App) |
| Aux Input | No |
| Bass Extension (-10dB) | 50Hz |
| Battery Life | 24 hours (Manufacturer specified) |
| Bluetooth | Yes |
| Bluetooth Codecs | SBC, AAC, LDAC |
| Bluetooth Latency | 110ms |
| Bluetooth Version | 5.0 |
| Digital Aux Input | No |
| Dimensions | 9.7” x 3.8” x 4.2” (246 x 97 x 106 mm) |
| Drivers | 2x 48x70mm X-Balanced racetrack drivers + 2x passive radiators |
| EQ | Yes (3 band) |
| IP Rating | IP67 |
| Lights | Yes |
| Maximum SPL | 97dB (measured by Alan Ross Reviews) |
| Omnidirectional | No |
| Party Mode | Yes (Party Connect up to 100 speakers) |
| Power Bank | Yes (USB-A) |
| Power Input | USB-C |
| Stereo | Yes |
| TWS | Yes |
| Weight | 2.4 lbs (1.1 kg) |
- Links
- Reviews, Comparisons and Sound Samples
- Alan Ross Reviews: Sony XB33 vs XB32 vs JBL Charge 4 best £120 bluetooth speaker? More from alanrossreviews →
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- Alan Ross Reviews: Sony xb33 vs xb43 vs Soundcore Motion Plus speakers test
- Alan Ross Reviews: JBL Charge 5 vs Motion Plus and Sony XB33 - ultimate travel speaker 2021 🤗
- Alan Ross Reviews: LG Xboom Go PL7 vs JBL Charge 4 and Sony XB33 - best Bluetooth speaker?
- Alan Ross Reviews: Tribit Xsound Mega vs the world! (JBL Charge 5, Bose Flex, Sony XB33, LG PL7) 👍
- GYMCADDY: Sony XE300 Review And Compared to Sony XB33 - A Muffled Mess More from GYMCADDY →
- Head-to-Head Comparisons
Ultimate Ears Boom 4: $129.99 Amazon $129.99 eBay
Older model: the Ultimate Ears Boom 3 (ranked lower, rated 2.9/5). See every Ultimate Ears Wonderboom, Boom and Megaboom generation.
Same family: the Ultimate Ears Wonderboom 4 (smaller model, ranked higher, rated 2.9/5) and the Ultimate Ears Megaboom 4 (larger model, ranked lower, rated 2.1/5).
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 →
| Released | Jun 2024 (2 years ago) |
|---|---|
| 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
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- Ultimate Ears Boom 4 vs Ultimate Ears Wonderboom 4
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- See all 139 comparisons