Bose
Bose SoundLink Flex (2nd Gen)
$159
Released 2024
Best Portable Speakers · head-to-head
Bose SoundLink Flex (2nd Gen) vs UE Boom 4
A sourced, side-by-side comparison. UE Boom 4 is cheaper at $149.99. Every spec and price links to its source.
Ultimate Ears
UE Boom 4
$149.99Cheaper
Released 2024
Which is better: the Bose SoundLink Flex (2nd Gen) or UE Boom 4?
On the specs we track, they're closely matched. The UE Boom 4 is the cheaper at $149.99.
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Full spec sheet
✓ marks the stronger figure where "more" — or "less", for price and weight — is unambiguously better.
| Spec | Bose SoundLink Flex (2nd Gen) | UE Boom 4 |
|---|---|---|
| US price | $159 | $149.99 |
| Brand | Bose | Ultimate Ears |
| Released | 2024 | 2024 |
| Battery hr | 12 | 15 |
| IP rating | IP67 | IP67 |
| Drivers | — | — |
| Bluetooth | 5.3 | — |
| Weight (lb) | 1.291 | — |
| Stereo pairing | Yes | Yes |
| Aux (in) | No | No |
| Release | 2024 | 2024 |
Sources — Bose SoundLink Flex (2nd Gen): bose.com (verified 2026-06-15). UE Boom 4: ultimateears.com (verified 2026-06-15).
What's the difference between the Bose SoundLink Flex (2nd Gen) and UE Boom 4?
Where the two actually differ on the specs we track (1 of 7). Matching specs are omitted.
- Battery hr: Bose SoundLink Flex (2nd Gen) 12 vs UE Boom 4 15
What reviewers say
Sourced tester consensus for each — the "what people who used it think" layer, not just specs.
Bose SoundLink Flex (2nd Gen)
Two whitelisted testers (SoundGuys, TechRadar) reviewed this exact model and both did hands-on testing. Both praise clean, balanced, detailed sound and the rugged IP67 build, but flag minimal upgrades over the 1st Gen, limited EQ options (only four presets), and unremarkable battery life. SoundGuys' standardized 80dB/1m test measured just 7 hours 3 minutes against Bose's 12-hour claim. (2 sourced reviews, 2 lab-tested.)
Praised: Clean, balanced, detailed sound with good instrument separation for its size; Rugged, durable IP67 dustproof/waterproof build for outdoor use; Attractive, portable design with strap/loop attachment.
Flagged: Minimal upgrades over the 1st Gen (near-identical hardware and sound profile); Limited EQ options in the app (only four presets); Underwhelming battery life; only ~12h claimed, and SoundGuys measured 7h 3min at 80dB.
UE Boom 4
No sourced tester review yet.