Short answer: the Soundlink Flex 2nd Gen, by a wide margin. At $159 it ranks #37 of 178 medium speakers. The Emberton III costs $20.99 more at $179.99 and ranks #125, a 64-place gap at essentially the same price.
The Emberton III’s own cons admit it barely moved. Our notes describe it as not really any different from the Emberton II except having the treble turned down a little, plus an unnatural echo-like coloration and bass that trails the competition. For a third generation, that’s a thin case for buying new over finding the older model discounted.
The Flex’s real weakness is battery drain, not sound. It’s described as pretty much identical to the first generation sonically, warm with boosted bass that can drown out midrange detail, but the more practical flaw is that it self-drains about 10% of its charge per week sitting unused.
Marshall’s advantage is battery life and materials. It claims 32 hours against the Flex’s 12, plus a fast quick-charge and an IP67 build using 50% recycled plastic, both real, measurable pluses if either specifically matters to you.
Buy the Soundlink Flex 2nd Gen for the better-ranked, better-sounding speaker. Buy the Emberton III only for the battery life and materials, not the sound.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
A small, rugged waterproof speaker with clear, well balanced mids, app EQ, aptX Adaptive and stereo pairing with a second unit.
A tough waterproof speaker with Marshall styling and a very long battery, plus quick charging.
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Specifications Side By Side
| Bose Soundlink Flex 2nd gen | Marshall Emberton III | |
|---|---|---|
| Price | $159.00 | $179.99 |
| Ranked | #37 of 178 in Medium Size Portable Bluetooth Speakers | #125 of 178 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Battery Life | 12 hours (Manufacturer specified) | 32 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| EQ | Yes (3 band) | Yes (3 presets via app) |
| IP Rating | IP67 | IP67 |
| Party Mode | Yes (Bose Party mode) | Yes (Marshall Stack) |
| Power Input | USB-C | USB-C |
| Stereo | No | Yes |
| Omnidirectional | No | Yes |
| TWS | Yes | No |
| Weight | 1.3 lbs (586 g) | 1.5 lbs (673 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Version | 5.3 | 5.3 |
| Dimensions | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) | 6.3” x 2.7” x 3” (160 x 68 x 76 mm) |
| Aux Input | No | No |
| Drivers | 60mm full-range driver with passive radiators | 2x 2” full-range cone drivers + 2x 2” passive radiators |
| Bluetooth Codecs | SBC, AAC, aptX Adaptive | SBC |
| Digital Aux Input | No | No |
| Strap | Yes (built-in loop) | No |
| Bass Extension (-10dB) | - | 62Hz |
| Power Bank | - | No |
| Amplifier Power | - | 20W |
Watch Them Compared
Videos and reviews that test both speakers side by side.
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