The JBL Boombox 3 Wi-Fi is a massive party speaker, the bigger alternative to the JBL Xtreme 3. It’s loud, it’s powerful and, unlike lots of JBL wireless speakers, it has Wi-Fi as well as Bluetooth.

This is a clear sign the JBL Boombox 3 is meant to be used at home a lot of the time, even though it does have a large internal battery. Don’t need Wi-Fi? JBL makes a version without too, and it is significantly cheaper – by about $150/£120.

At this size you do lose a lot of the portable charm of series like the JBL Flip and, yes, even the Xtreme 3. You probably wouldn’t want to lug the Boombox 3 around all that often, and it does cost a lot, $649.95/£519.99 at launch. However, it also sounds great and has the power you’d expect from a glance at this extra-large wireless speaker, not to mention its name.

Design

• IP67 water resistance
• Classic aggressive JBL design
• Metal handle

The number one tip for prospective JBL Boombox 3 buyers: don’t underestimate its weight and heft. This speakers weighs 6.7kg, three times as much as the Xtreme 3, which is already considered a large speaker.

You are unlikely to want to move the JBL Boombox 3 around all that often. And it doesn’t have a shoulder strap like the Xtreme 3, just a whacking great big handle along the top.

It does, thanks to all that weight, feel sturdy. The construction is much like that of some of JBL’s smaller models – a large part of the frame is covered by a tough nylon fabric weave, the handle is aluminium and the rest is mostly plastic. There are also rubbery strips along its bottom and under the handle, for improved grip, and some rubberdised controls along the top.

It’s a familiar design for any of the long-term JBL fans out there. And, as ever, the sides become the focal point in use.

A passive radiator sits at each end. This is a kind of speaker driver that reacts to air moved around by the other drivers, pushing the radiator in and out to dramatically improve bass output. These go wild when you put a bassy track on and crank the volume, pumping in and out like pistons and making for quite the showpiece.

Features

• Multi-room support
• 24-hour battery life
• IP67 water resistance

The built-in Wi-Fi sets the Boombox 3 Wi-Fi apart from most of the smaller speakers in the JBL line, and this series’ predecessors.

Sure, you can use it like a Bluetooth speaker too. But when given access to your home Wi-FI network through the JBL One app, it can also use Spotify Connect, Chromecast streaming and become part of a Google Home multi-room setup, widening its use cases significantly.

We still think the Boombox 3’s design is a little brash and aggressive to slot into the average grown-up living room, though. It comes across a bit like the day rave version of the B&W Zeppelin.

Do consider whether you’ll actually want this 50cm-long party speaker on display in your home 24/7, and bear in mind too that there is no HDMI for connection to a TV, or an aux input to plug into a laptop.

But Wi-Fi means its functionally right up there with the top home wireless-only speakers.

It’s an indoors-outdoors hybrid, but one with limits – not least because of its weight and dimensions. Still, the internal battery lasts up to an excellent 24 hours, and a USB port under the flap on the back lets you use it as a power bank if you’re in a pinch.

That flap is also rubber-sealed, making the JBL Boombox 3’s top-tier IP67 water-resistance viable. It won’t float in water, but it will take a drenching.

Sound quality

• Powerful 40Hz sub-bass
• Good separation for a wireless speaker
• Somewhat limited sound customisation

Earlier we said the side-mounted passive radiators were spotlight-stealers of the Boombox 3 design. They also deliver the most notable part of the sound.

Deep bass is the reason the Boombox 3 is quite so much larger than the Xtreme 3. JBL says it can reach 40Hz. Using a tone generator we heard the first stirrings of substantive bass output at 35Hz, with a good solid rumble at 40Hz.

This low-bass power, just as promised, helps give the speaker’s sound an authority most portable speakers simply don’t have. The typical reaction is to put on some electronic dance music peppered with sub-bass drops to put the Boombox 3 through its paces. But a low bass floor helps with virtually all kinds of music. Any time a kick drum is hit, you hear the subwoofer-like depth of the lower frequencies. It’s thrilling stuff.

Having that extension also means the JBL doesn’t have to load up the speaker with excessive upper-register bass in order to get that heart-racing “bassy” feel the name seems to promise. Doing that is what often leads to a muddy and cluttered sound, with big and boomy bass that seems to engulf the mids in order to seem bassy.

There’s none of that here, or at least very little of it. Much like the JBL Xtreme 3, the Boombox 3 has a slightly warmer, more bottom-heavy sound than some of the earlier speakers tuned to the “JBL Pro” standard. However, this speaker is still a lot more refined than you might expect given its brash appearance — if not less than we’d expect given the substantive cost.

Separation and a sense of openness to the bass and upper registers are both excellent for a speaker of this class. That combo of muscular low bass and a sense of elegance in areas where power isn’t the most obvious and winning characteristic mean the Boombox 3 can easily be your home’s main music speaker.

No kind of music seems poorly served by it – it’s so capable that you end up wishing this sound could provide a proper stereo image. However, while the JBL Boombox 3 does have separate left and right drivers, for both the treble and the mids, they are only separated by less than 30cm, You just can’t get anything like the effect of a pair of classic speakers, or a pair of stereo paired Sonos Era 100s.

If I put my audiophile hat on, the Sonos Boombox 3 does have both a slight granularity to the upper mids too, and at times the standard-register mids sound as thought they could do with a little more prominence. JBL does let you do this, sort of, using EQ baked into the JBL One app.

This is, unfortunately, pretty basic, with just three bands of equalisation. Bass, mids, treble – that’s your lot. You could argue this is JBL having confidence in its tuning, but these rudimentary controls make it tricky to do what I’d hoped – to slim down the mid-bass a touch and bring up the mids a little, to let certain male-register vocals shine a litte better better.

I fiddled around for a few hours, but ultimately couldn’t get anything significantly better than the standard tuning. That said, being able to drop down the bass is handy for when you don’t want to listen at whisper volume but also don’t want those 40Hz sonic booms to sail through walls and floors.

That means if you’re worried about the neighbours complaining, this party monster can be tamed, at least temporarily.

Verdict

The JBL Boombox 3 Wi-Fi is, for some tastes, comfortably the best-sounding model in JBL’s mainstream line-up. It flings out seriously deep thrilling bass without becoming mired in the stuff.

This is also perhaps the JBL speaker in this mould with the narrowest appeal, though. Moving this thing around feels a lot like lugging around a kettlebell, and I’dd recommend the JBL Xtreme 3 instead if you want a loud and brawny speaker you can comfortably carry around boombox-style.

It also costs a lot for something I’m not sure many would give prize place in their living room – a big reason to buy this Wi-Fi version over the standard option. However, there’s still something undeniably impressive about the sound and power the JBL Boombox 3 is capable of, especially when matched with all-day battery life and shrug-off-a-rainstorm IP67 water resistance.