Short answer: the Bogasing M5. It ranks #61 of 177 medium speakers by sound quality, rated 3.5/5, at $52.99; the Sony ULT Field 3 ranks #71, rated 3.4/5, and costs $208, which makes this an easy call rather than a real tradeoff.
What the Sony ULT Field 3 does well: A rugged waterproof stereo speaker with long battery life, a detailed app EQ, a shoulder strap and a phone charging port. It plays in stereo from a single unit, unlike the Bogasing M5. The tradeoff: Sounds a bit hollow, a bit boosted in the treble.
The Bogasing M5 is the lighter option. A compact, backpack friendly speaker with very long battery life and USB-C charging at a budget price. At 1.7 lbs (757 g) it weighs noticeably less than the Sony ULT Field 3 at 2.6 lbs (1.2 kg). It keeps a wired aux input, which the Sony ULT Field 3 lacks. The tradeoff: Front/rear driver configuration.
Buy the Bogasing M5. It is rated higher for sound quality than the Sony ULT Field 3 and costs less, so only choose the other one for a particular feature it does better.
Looking for alternatives? See the complete Portable Bluetooth rankings.
A rugged waterproof stereo speaker with long battery life, a detailed app EQ, a shoulder strap and a phone charging port.
A compact, backpack friendly speaker with very long battery life and USB-C charging at a budget price.
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
| Sony ULT Field 3 | Bogasing M5 | |
|---|---|---|
| Price | $208.00 | $52.99 |
| Ranked | #71 of 177 in Medium Size Portable Bluetooth Speakers | #61 of 177 in Medium Size Portable Bluetooth Speakers |
| App | Yes | No |
| Aux Input | No | Yes |
| Battery Life | 24 hours (Manufacturer specified) | 30 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC, LDAC | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.2 | 5.3 |
| Built-in Microphone | Yes | - |
| Dimensions | 10.1” x 4.4” x 3.1” (256 x 113 x 79 mm) | 6.3” x 3” x 2.8” (160 x 76 x 71 mm) |
| Drivers | 1x 20mm tweeter + 1x 86mm x 46mm woofer | 30W system |
| EQ | Yes (App + ULT button) | Yes |
| IP Rating | IP67 | IPX7 |
| Party Mode | Yes (Party Connect up to 100 speakers) | - |
| Power Bank | Yes (USB-C, 5V/1.5A) | Yes (USB-A) |
| Power Input | USB-C | USB-C |
| Stereo | Yes | No (front/rear drivers) |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 2.6 lbs (1.2 kg) | 1.7 lbs (757 g) |
| Amplifier Power | 27W | 40W |
| Digital Aux Input | No | No |
| Strap | Yes (detachable shoulder strap) | - |
| Bass Extension (-10dB) | - | 61Hz |
| Maximum SPL | - | 96dB (measured by Alan Ross Reviews) |
| MicroSD Playback | - | Yes |
| USB Playback | - | Yes |
| Frequency Response | - | 50Hz - 20kHz (Manufacturer specified) |
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