JBL is one of the strongest contenders in the portable Bluetooth speaker market, with its Charge range asking questions of well established rivals such as the Ultimate Ears Boom 3.

The late-2019 entry to the series, the JBL Charge 4, increases a little in size over its predecessor. Its intent: to deliver bold sound and battery life that'll last on and on. Its passive radiators also mean bags of bass - well beyond what you'd expect from a little cylindrical speaker such as this.

Our quick take

No, it's not the prettiest Bluetooth speaker out there. But it is very portable, rugged, waterproof, has epic battery life, and sound that'll blow your socks off - especially considering its small scale. All that makes it easy to recommend the JBL Charge 4.

Design

• Dimensions: 220 x 95 x 93mm / Weight: 960g
• Ports: USB-C charging, 3.5mm in, USB-A out
• Durable fabric and rubberised design
• Physical control buttons up top
• IPX7 waterproofing

To look at, however, we're not exactly in love with the JBL Charge 4. It looks fine enough, but it's hardly standout in a world occupied by so many fancier-looking alternatives. We don't know, maybe it's the weird translucent rubberised edging, maybe it's the camo green paint work of our review sample and the distracting orange badge that's front an centre.

Either way, those rugged looks are backed up by genuine rugged construction. With IPX7 waterproofing you could lob this speaker in a puddle or pool and not fret. Which you might think shows the intent of this speaker's use - in an outdoors setting - but its molded foot actually sees it sit best on a table really.

Up top are the various controls - the centre for on/off and Bluetooth pairing, along with volume, play/pause and multi-speaker pairing. These are easy to use, emit clear sounds when searching for a device and we've found the Bluetooth signal to be strong throughout use.

Around the back, hidden behind a cover - necessary to assure the waterproofing - is where you'll find the ports. There's a USB so you can plug in a device, such as your phone, to draw the power from the speaker - which is one of the features version 4 adds over its predecessor. There's a wired 3.5mm jack if you don't want to use Bluetooth too.

There's also a USB-C port used for charging. But while this comes with a cable in the box, there's no plug. Which is a problem because the Charge 4 needs ample power delivered to recharge. Plug into a laptop and it's no good. Plug into those 5V USB sockets that you get on some plug sockets and, again, no dice. Recharging also takes a rather long time, at over four hours.

That's because the on-board battery is rather large, able to push its way through up to 20 hours of playback - a 25 per cent boost over its predecessor. At middling volume there's no problem to get that far, but crank the output up and it'll be a little less. Still, that's very good innings for a portable speaker - and good job, as we suspect you won't be able to recharge it from most portable powerbanks.

Sound

• Frequency response: 60Hz – 20,000Hz
• Dual passive radiators to boost bass
• 7,500mAh battery - 20hrs playback
• Bluetooth 4.2 wireless
• JBL Connect+ app

Despite its cylindrical shape, the JBL Charge 4 doesn't output sound equally through 360 degrees like some of its competition. There's still a wide-angle output, though, ensuring you'll get decent quality throughout the room.

And the sound is really rather large. For a speaker as small as this it hits all the right notes, low to high, creating a soundstage that demands attention.

The volume 'jumps' between each stage are a bit dramatic though, there's not the dynamic subtlety here that you can find in the competition. The sound, however, is rather dynamic - able to crank out bass with impact, without it drowning out measured mids and highs.

The bass is massaged by those twin passive radiators - one at each end of the tube - that you'll see vibrating gleefully when the low-end is in effect. JBL claims a low-end minimum of 60Hz, which isn't as technically low as you'll find in some speaker setups, but most tracks aren't going to delve into much that's lower on the frequency scale anyway.

There's also the JBL Connect+ app available, should you wish to pair your JBL speaker with another for using in stereo mode, or pair it with yet more (up to 100, apparently, which we're sure nobody has ever done).

To recap

No, it's not the prettiest portable Bluetooth speaker. But it is very portable, rugged, waterproof, has epic battery life, and sound that'll blow your socks off - especially considering its small scale. All that makes it easy to recommend.