We have just come across these speakers and, while we're hardly in audiophile territory here, you won't believe the amount of sound that you can get out of them for the price.
There's a section at the top of RedShark Sound for Higher Audio, which is where we talk about all aspects of superb audio recording and reproduction. This bargain Bluetooth speaker won't be going in there.
For the money, it's remarkable. A full, heavy, aluminum chassis, nice industrial design and – this is what really matters – it's loud without sounding terrible. There are no nuances with this speaker: it's much too small for that, but for its size (19.9 x 6 x 5.7 cm) and weight (717gm), it is remarkably good. Remember, at this price (around £44/$60), it's amazing.
The speaker is battery powered and rechargeable. The manufacturer claims that the (generous) 4000 mAH battery will last for six hours.
Please don't expect to get audiophile - or even particularly good - performance from these speakers. But you can't measure these little marvels in conventional terms.
Just pumping out the volume without sounding nasty is good enough for me at this price. They're definitely worth a try if you're looking for something ultra portable to take with you on holiday or even a video editing gig, where you need some tough, compact, self-powered speakers that probably aren't that different from those you'd find in a small TV set.
(BTW - I only paid £31 for mine. As soon as I'd ordered them, the price went up by twelve pounds. I guess Amazon prices some of these products dynamically through some unfathomable algorithm. Anyway, if you want to buy them, it might be worth going back on different days or even checking them from someone else's Amazon account.)