When you look at the JBL Xtreme, you see something of a brute. Its broad shoulders and barrel chest promise power, and it feels tough, too.
The passive bass radiators at either end of the drum are the only areas in which you'd feel tentative about poking around, the rest you feel could be subjected to a considerable amount of torture.
That heavyweight material adds a little to its weight (2.1kg), but it remains a manageable size and there's a strap in the box for easy carrying.
It isn't fussed by rain, either; as usual splashproof doesn't mean entirely waterproof – no submerging – but JBL is quite happy with you washing the Xtreme under a running tap.
There is a charge point, auxiliary input and two USB outputs for your phone to share in some of the Xtreme's claimed 15-hour battery life – but they’re not waterproof, so keep them dry.
More after the break
We're eager to put all this muscle to good use, but start with something more low key: The Tallest Man On Earth's Love Is All. The JBL captures the lo-fi recording nicely – the guitar warbles and the room is laid bare – but there's a richness that keeps the sound from becoming clinical.
The solidity doesn't compromise dynamics, either. The guitar strings are allowed to bounce with the rhythm of Kristian Matsson's finger picking. His vocal is similarly expressive and keeps its charm despite a thin recording.
Then the opening guitar hook of Ryan Adams's Gimme Somethin' Good slashes its way through, followed by a thumping drum kit.
A good wireless speaker is indiscriminate about the music it plays best, so let's just say the Xtreme feels very comfortable. The vocal is equally bold, and the sound is undeniably big; it is the power we were expecting at first glimpse.
If there is a criticism to be made, it is that the low end, considerable as it is, doesn't quite show the agility or lightness of feet we'd really like.
The detail shown throughout the rest of the frequency range is lacking down there and when we shift to a song in which the energy comes from a dancing bass line, such as Bedouin Soundclash's Gyasi Went Home, we'd like a little more composure.
To tighten things up, we try a range of tables, a bookcase, speaker stands and the floor. The results vary, but we are never truly satisfied. A more practical solution, given the absence of options, is to adjust the EQ on your phone or music player.
We'd certainly recommend you take a listen; you may find the Xtreme's fortes, of which it has many, justify a little of your own work to find the right balance.
If so, this is a versatile wireless speaker with which you can certainly have a lot of fun.
See all our JBL reviews