What should you expect from a "multimedia" speaker that costs $20? Well, for starters, no stereo sound, because the Logitech Z50 is a single speaker. And not something that delivers deep bass because the Z50 is pretty small -- about the size of a coffee mug sliced off at an angle at the top, with only one upward-firing driver. And, no, don't look for wireless capabilities, either.
On the plus side, the speaker is fairly attractive (it comes in three different color options), is very easy to set up and use, and due to its pencil-cup look, seems at home on an office desk.
To get going, you simply plug the small AC adapter into an outlet and then connect the the hard-wired 3.5mm audio line to your computer, smartphone, or tablet (or any other device that has a 3.5mm audio output or headphone input). The Z50's specs say that it has 10-watt peak power, which is pretty potent considering its small footprint.
Its biggest strength is that it plays loud for its size and sounds reasonably clear. As noted, it's a little light on the bass and it will distort at higher volumes, especially on bass heavy tracks. It did fine with ballads like John Legend's "All of Me" track. But when I cranked the American Authors' "Best Day of My Life," the little speaker didn't have the best day of its life (it distorted in spots, so I lowered the volume).
Though it isn't stereo, it sounds better and is a significant upgrade over the vast majority of integrated laptop and other mobile device speakers. I also thought it sounded as good or better than some of the compact $50-$70 Bluetooth speakers I've reviewed and overall, it exceeded my expectations, though they were pretty low to begin with. It'd be fine for video watching and casual music listening. I'd call it a good speaker for kids, but the driver on the top is exposed and might get punctured if you dropped anything heavy or sharp on it.
For better or worse, The Logitech Z50 has no battery-powered option or a USB digital connection that would also provide power. But for 20 bucks, it's a decent enough little mono speaker. If you're looking for better sound -- or actual stereo separation, at least -- you can check out Logitech's Z130, Z150, or Z200 stereo speakers, which retail at $13, $20, or $30 online, respectively. But the Z50 will appeal to those looking for a small speaker that's simple to set up and takes up very little space on a desk.