These are not really the same size class, and that is the honest framing here. The Marshall Middleton II ranks #31 of 120 large speakers by sound quality at $279.99; the Bose Soundlink Flex 2nd gen ranks #37 of 179 medium speakers by sound quality at $159.
The Marshall Middleton II is the longer-running option. A waterproof stereo speaker with very deep bass for its size, a long battery, a power bank and an app EQ. It is rated for 30 hours of battery against 12 for the Bose Soundlink Flex 2nd gen. It keeps a wired aux input, which the Bose Soundlink Flex 2nd gen lacks. It plays in stereo from a single unit, unlike the Bose Soundlink Flex 2nd gen. The tradeoff: Bass boosted which drowns out the midrange.
The Bose Soundlink Flex 2nd gen is the lighter option. A small, rugged waterproof speaker with clear, well balanced mids, app EQ, aptX Adaptive and stereo pairing with a second unit. At 1.3 lbs (586 g) it weighs much less than the Marshall Middleton II at 4 lbs (1.8 kg). It supports aptX Adaptive Bluetooth, which the Marshall Middleton II lacks. The tradeoff: One Flex remains mono and cannot deliver genuine low-bass rumble; RTINGS also found the elevated treble can turn hi-hats and other high-frequency detail piercing.
Buy the Marshall Middleton II at $279.99 if you want a large speaker. Buy the Bose Soundlink Flex 2nd gen at $159 if you want a medium speaker instead.
Still deciding? The full Portable Bluetooth rankings cover every ranked option.
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.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| Marshall Middleton II | Bose Soundlink Flex 2nd gen | |
|---|---|---|
| Price | $279.99 | $159.00 |
| Ranked | #31 of 120 in Large Size Portable Bluetooth Speakers | #37 of 179 in Medium Size Portable Bluetooth Speakers |
| App | Yes | Yes |
| Aux Input | Yes | No |
| Bass Extension (-10dB) | 38Hz | - |
| Battery Life | 30 hours (Manufacturer specified) | 12 hours (Manufacturer specified) |
| Built-in Microphone | Yes | Yes |
| EQ | Yes (5 band) | Yes (3 band) |
| IP Rating | IP67 | IP67 |
| Party Mode | Yes (Marshall Stack) | Yes (Bose Party mode) |
| Power Bank | Yes (USB-C) | - |
| Power Input | USB-C | USB-C |
| Weight | 4 lbs (1.8 kg) | 1.3 lbs (586 g) |
| Bluetooth | Yes | Yes |
| Bluetooth Codecs | SBC | SBC, AAC, aptX Adaptive |
| Stereo | Yes | No |
| Omnidirectional | No | No |
| TWS | Yes | Yes |
| Bluetooth Version | 5.3 | 5.3 |
| Dimensions | 9.1” x 3.9” x 4.3” (230 x 98 x 110 mm) | 7.9” x 3.5” x 2” (201 x 90 x 52 mm) |
| Drivers | 2x 75mm woofers, 2x 0.625” tweeters + 2x passive radiators | 60mm full-range driver with passive radiators |
| Frequency Response | 50Hz - 20kHz (Manufacturer specified) | - |
| Amplifier Power | 80W | - |
| Digital Aux Input | No | No |
| Strap | Yes (detachable strap) | Yes (built-in loop) |
Related Speaker Comparisons
More top alternatives to Bose Soundlink Flex 2nd gen: