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 1 ranks #99, rated 3.1/5, and costs $108, which makes this an easy call rather than a real tradeoff.
The case for the Sony ULT Field 1: A tough, waterproof small speaker that survives drops, with long real world battery life and stereo pairing. Watch for: Upper midrange peak, rolled off treble.
The Bogasing M5 is the better-sounding, longer-running option. A compact, backpack friendly speaker with very long battery life and USB-C charging at a budget price. It is rated for 30 hours of battery against 12 for the Sony ULT Field 1. It keeps a wired aux input, which the Sony ULT Field 1 lacks. The catch: Front/rear driver configuration.
Buy the Bogasing M5. It is rated higher for sound quality than the Sony ULT Field 1 and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Portable Bluetooth rankings.
A tough, waterproof small speaker that survives drops, with long real world battery life and stereo pairing.
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 1 | Bogasing M5 | |
|---|---|---|
| Price | $108.00 | $52.99 |
| Ranked | #99 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 | 12 hours (Manufacturer specified) | 30 hours (Manufacturer specified) |
| Built-in Microphone | Yes | - |
| EQ | Yes | Yes |
| IP Rating | IP67 | IPX7 |
| Party Mode | Yes (Party Connect up to 100 speakers) | - |
| Power Bank | No | Yes (USB-A) |
| Power Input | USB-C | USB-C |
| Stereo | No | No (front/rear drivers) |
| Omnidirectional | No | Yes |
| TWS | Yes | Yes |
| Weight | 1.4 lbs (650 g) | 1.7 lbs (757 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | AAC, SBC | SBC (inferred; additional codecs unverified) |
| Bluetooth Version | 5.3 | 5.3 |
| Dimensions | 8.1” x 3” x 3” (206 x 77 x 76 mm) | 6.3” x 3” x 2.8” (160 x 76 x 71 mm) |
| Drivers | 83mm x 42mm woofer, 16mm tweeter + passive radiator | 30W system |
| Digital Aux Input | No | No |
| Strap | Yes (detachable 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) |
| Amplifier Power | - | 40W |
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