Short answer: the Sony ULT Field 5. It ranks #56 of 115 large speakers by sound quality, rated 3.5/5, at $268. The Marshall Stockwell III ranks #79, rated 3.0/5, at $249.99, $18.01 cheaper, a saving that is not big enough to make up the sound-quality gap.
The Sony ULT Field 5 is the better-sounding, tougher choice. A tough, waterproof party speaker with loud, bass focused output, an aux input, a power bank and a long battery. It is rated IP67 against IP55 for the Marshall Stockwell III. It supports LDAC Bluetooth, which the Marshall Stockwell III lacks. The tradeoff: It prioritizes bass and loudness over fidelity: reviews find the upper mids and highs subdued, with limited stereo separation and soundstage depth.
The Marshall Stockwell III is the longer-running, lighter choice. A stylish, rugged speaker with a very long battery you can swap yourself, a detailed app EQ, and power bank charging. It is rated for 40 hours of battery against 25 for the Sony ULT Field 5. At 2.9 lbs (1.3 kg) it weighs much less than the Sony ULT Field 5 at 7.3 lbs (3.3 kg). The tradeoff: Highs are recessed by default and need the treble control maxed to compensate, still lacking detail even then.
Buy the Sony ULT Field 5. It is rated higher for sound quality, and the $18.01 you would save on the Marshall Stockwell III does not close the gap.
Looking for alternatives? See the complete Portable Bluetooth rankings.
A tough, waterproof party speaker with loud, bass focused output, an aux input, a power bank and a long battery.
A stylish, rugged speaker with a very long battery you can swap yourself, a detailed app EQ, and power bank charging.
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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| Sony ULT Field 5 | Marshall Stockwell III | |
|---|---|---|
| Price | $268.00 | $249.99 |
| Ranked | #56 of 115 in Large Size Portable Bluetooth Speakers | #79 of 115 in Large Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | Yes | Yes |
| Battery Life | 25 hours (Manufacturer specified) | 40+ hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, AAC, LDAC | SBC, AAC, LE Audio with LC3 |
| Bluetooth Version | 5.3 | 5.3 |
| Built-in Microphone | Yes | - |
| Dimensions | 12.6” x 5.7” x 4.9” (320 x 144 x 125 mm) | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) |
| Drivers | 2x 46mm tweeters + 1x 79mm x 107mm woofer | 1x 3” woofer, 2x 1.75” wide-band drivers |
| EQ | Yes (App + ULT button) | Yes (parametric, via app) |
| IP Rating | IP67 | IP55 |
| Party Mode | Yes (Party Connect up to 100 speakers) | - |
| Power Bank | Yes (USB-C) | Yes |
| Power Input | USB-C | USB-C |
| Stereo | Yes | Partially |
| Omnidirectional | No | Yes |
| TWS | Yes | No |
| Weight | 7.3 lbs (3.3 kg) | 2.9 lbs (1.3 kg) |
| Amplifier Power | 27W | 44W |
| Digital Aux Input | No | No |
| Strap | Yes (detachable shoulder strap) | Yes (detachable strap) |
| Frequency Response | - | 54Hz - 20kHz (Manufacturer specified) |
Related Speaker Comparisons
More worthwhile head-to-heads for Sony ULT Field 5: