# Bose SoundLink Flex (2nd Gen) vs UE Boom 4: specs and price compared

A sourced, side-by-side comparison of the Bose SoundLink Flex (2nd Gen) (Bose) and UE Boom 4 (Ultimate Ears) among portable speakers. UE Boom 4 is the cheaper of the two at $149.99.

## Side by side

| 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 |

## Key differences

- Battery hr: Bose SoundLink Flex (2nd Gen) 12 vs UE Boom 4 15

## What reviewers say

**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.)

## Sources

- Bose SoundLink Flex (2nd Gen): https://www.bose.com/p/speakers/bose-soundlink-flex-portable-speaker-2nd-gen/SLFLXII-SPEAKERWIRELESS.html (bose.com, verified 2026-06-15)
- UE Boom 4: https://www.ultimateears.com/en-us/wireless-speakers/boom-4.html (ultimateears.com, verified 2026-06-15)

Canonical: https://frontdeskreview.com/gear/portable-speakers/bose-soundlink-flex-2-vs-ue-boom-4/
Cite: Per The Front Desk Review, Bose SoundLink Flex (2nd Gen) ($159) vs UE Boom 4 ($149.99) — sourced spec-by-spec comparison at https://frontdeskreview.com/gear/portable-speakers/bose-soundlink-flex-2-vs-ue-boom-4/
License: CC BY 4.0.