Bose SoundLink Flex (2nd Gen) Review

The Bose SoundLink Flex (2nd Gen) is the follow-up to Bose's hugely popular compact portable speaker, priced at around £130. It keeps the winning formula — a pocketable, ruggedly built Bluetooth speaker that punches well above its size — while adding the refinements the original lacked, namely an app with adjustable EQ and support for the AAC and aptX codecs. Independent laboratory testing rates it a genuinely good little outdoor speaker, with a couple of predictable limits for its size.

Bose's party trick here is getting a big, balanced sound out of a very small box. The test found it a well-judged performer for its size, with the warm, clear signature Bose is known for. A clever PositionIQ feature detects whether the speaker is standing upright, lying flat or hanging, and automatically adjusts the sound to suit — so it always sounds its best however you place it. The 2nd Gen's new app adds an adjustable equaliser, so you can tune the balance to taste rather than being stuck with the default, a welcome upgrade over the original.

This is where the SoundLink Flex shines. The test praised its remarkable portability and excellent build quality, making it an easy choice for park hangs, picnics and hikes. Crucially, it carries an IP67 rating, meaning it is fully dustproof and can survive being dropped into a shallow puddle — not just splashes. A soft silicone body resists knocks, and an integrated loop lets you clip the side strap to a backpack or bag. It is the kind of speaker you can throw in a rucksack without a second thought.

The 2nd Gen brings the meaningful upgrades. Alongside the EQ app, it adds AAC and aptX codec support for higher-quality wireless streaming from compatible phones, and switches to USB-C charging. On battery, the test measured around six to seven hours of real-world playback — enough for most days out, if a little short of Bose's headline figure, so heavy users may want to top up. You can also pair two units for a proper stereo pair.

The compromises are the honest ones for a speaker this small. The test noted it does not get especially loud, so it is better suited to personal listening and small gatherings than filling a garden at a party. And because its drivers fire forwards rather than all around, it does not produce the 360-degree sound some rivals offer — and you need a second unit for true stereo. Neither undermines its core appeal as a grab-and-go speaker.

The Bose SoundLink Flex (2nd Gen) is a strong compact pick in our best Bluetooth speakers guide. It goes head-to-head with the JBL Flip 7 and the rugged Ultimate Ears WONDERBOOM 4, trading a little volume for Bose's build quality and balanced sound, and with the style-led Marshall Emberton III. Anyone wanting more volume and 360-degree sound should step up to the larger Ultimate Ears MEGABOOM 4. Check the price on Amazon

The Bose SoundLink Flex (2nd Gen) is a lovely little speaker that does the important things brilliantly: it is superbly built, genuinely rugged, easy to carry and sounds far bigger than it looks, and the added EQ app and better codecs address the original's main gaps. It will not fill a party and it lacks 360-degree sound, but as a rugged, take-anywhere personal speaker it is one of the best compact options going. For picnics, showers and travel, it is an easy recommendation.

This review is based on independent laboratory testing rather than our own hands-on trial.