These sit in different size classes, so this is not a straight ranking comparison. The JBL Boombox 4 ranks #20 of 113 boombox speakers by sound quality at $549.95; the Marshall Stockwell III ranks #84 of 120 large speakers by sound quality at $249.99.
Different sizes. The Boombox 4 is a 13.2 lbs (6 kg) boombox. The Stockwell III is a 2.9 lbs (1.3 kg) large speaker. Each is rated within its own class.
The Boombox 4 measured about 115dB with bass to about 41Hz, is IP68, and claims 28 hours from a removable battery. Use the Oluv EQ linked on its page, since the stock tuning sounds worse than the Boombox 3.
The Stockwell III sounds muffled by default with boomy bass, and turns harsh well below maximum volume. It offers over 40 hours of claimed battery, a replaceable battery, an aux input and a parametric app EQ.
Buy the JBL Boombox 4 at $549.95 if you want a boombox speaker. Buy the Marshall Stockwell III at $249.99 if you want a large speaker instead.
Water resistance is not close: the JBL Boombox 4 is rated at IP68 (extended submersion), well ahead of the Marshall Stockwell III at IP55 (water jets).
Want more options? Browse the full Portable Bluetooth rankings.
Prices on this page were last checked November 7, 2026 at 7:34 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
| JBL Boombox 4 | Marshall Stockwell III | |
|---|---|---|
| Price | $549.95 | $249.99 |
| Ranked | #20 of 113 in Boombox Size Portable Bluetooth Speakers | #84 of 120 in Large Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | No | Yes |
| Bass Extension (-10dB) | 41Hz | - |
| Battery Life | 28 hours (Manufacturer specified) | 40+ hours (Manufacturer specified) |
| EQ | Yes (7 band) | Yes (parametric, via app) |
| IP Rating | IP68 | IP55 |
| Bluetooth Latency | AAC 144ms, SBC 48ms | - |
| Maximum SPL | 115dB (measured by Alan Ross Reviews) | - |
| Party Mode | Yes (Auracast) | - |
| Power Input | AC Power cord | USB-C |
| Removable Battery | Yes | - |
| Stereo | Yes | Partially |
| Omnidirectional | No | Yes |
| Weight | 13.2 lbs (5.98 kg) | 2.9 lbs (1.3 kg) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC, LC3, AAC | SBC, AAC, LE Audio with LC3 |
| Bluetooth Version | 5.4 | 5.3 |
| Built-in Microphone | No | - |
| Power Bank | Yes (USB-C, up to 30W) | Yes |
| TWS | Yes | No |
| Digital Aux Input | Yes (USB-C) | No |
| USB Playback | No | - |
| FM Tuner | No | - |
| Microphone Input | No | - |
| MicroSD Playback | No | - |
| Amplifier Power | 210W AC / 200W battery | 44W |
| Dimensions | 20.1” x 10.2” x 8.3” (510 x 260 x 210 mm) | 7.1” x 6.4” x 2.9” (180 x 162 x 74 mm) |
| Drivers | 2x 123mm woofers + 2x 20mm tweeters with passive radiators | 1x 3” woofer, 2x 1.75” wide-band drivers |
| Strap | No | Yes (detachable strap) |
| Frequency Response | - | 54Hz - 20kHz (Manufacturer specified) |
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