Short answer: the Onn Portable FM Boombox. It ranks #26 of 115 large speakers by sound quality, rated 4.2/5, at $74.83; the Marshall Stockwell III ranks #79, rated 3.0/5, and costs $249.99, so there is little reason to consider the other one.
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 16 for the Onn Portable FM Boombox. At 2.9 lbs (1.3 kg) it weighs much less than the Onn Portable FM Boombox at 4.9 lbs (2.22 kg). It has an adjustable EQ, which the Onn Portable FM Boombox lacks. The tradeoff: Highs are recessed by default and need the treble control maxed to compensate, still lacking detail even then.
The Onn Portable FM Boombox is the better-sounding, tougher pick. An excellent value waterproof boombox that floats, with reasonably deep bass, FM radio, lights and a long battery. It is rated IPX7 against IP55 for the Marshall Stockwell III. The tradeoff: Reasonable frequency response, but not quite as smooth as some of the top-ranked speakers in this size.
Buy the Onn Portable FM Boombox. It is rated higher for sound quality than the Marshall Stockwell III 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 stylish, rugged speaker with a very long battery you can swap yourself, a detailed app EQ, and power bank charging.
An excellent value waterproof boombox that floats, with reasonably deep bass, FM radio, lights and a long battery.
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
| Marshall Stockwell III | Onn Portable FM Boombox | |
|---|---|---|
| Price | $249.99 | $74.83 |
| Ranked | #79 of 115 in Large Size Portable Bluetooth Speakers | #26 of 115 in Large Size Portable Bluetooth Speakers |
| Drivers | 1x 3” woofer, 2x 1.75” wide-band drivers | 2 speakers |
| Frequency Response | 54Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 44W | 25W RMS (100W peak) |
| Battery Life | 40+ hours (Manufacturer specified) | 16 hours (Manufacturer specified) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | - |
| Bluetooth Codecs | SBC, AAC, LE Audio with LC3 | SBC (inferred; additional codecs unverified) |
| IP Rating | IP55 | IPX7 |
| Weight | 2.9 lbs (1.3 kg) | 4.9 lbs (2.22 kg) |
| Dimensions | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) | 13.8” x 5.9” x 7.7” (350 x 149 x 195 mm) |
| App | Yes | No |
| EQ | Yes (parametric, via app) | No |
| Aux Input | Yes | Yes |
| Digital Aux Input | No | No |
| Power Bank | Yes | Yes (USB-A) |
| Power Input | USB-C | USB-C |
| Stereo | Partially | Yes |
| Omnidirectional | Yes | No |
| TWS | No | Yes |
| Strap | Yes (detachable strap) | - |
| FM Tuner | - | Yes (10 presets) |
| Built-in Microphone | - | Yes |
| Party Mode | - | Yes (Party Sync, pairs with 1 other onn. speaker) |
| Removable Battery | - | No |
| Lights | - | Yes |
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