» What it is: A small-in-size, big-in-sound portable speaker made by Divoom. The internal rechargeable battery spits out power for eight hours, and the "audio out" port means you can impart Bluetooth capability to other speakers with this one. It has a microphone toggle button so you can take phone calls via Bluetooth.

» The good: The audio science of smaller and smaller speakers with bigger sound fascinates me because I’m always looking for the most easily packable, biggest-sounding speaker I can find. Standing 2 3/4 inches high, this one’s a beaut. There simply is nothing like playing your favorite music in new settings the world over. This comes with a cable for non-Bluetooth devices, but the Bluetooth range is impressive: It’s advertised to function at 30 feet. It does all of that. It has much better bass than other speakers this size, but don’t expect that throb you might get from a box speaker; this simply generates the range of sound you expect from your music. For good measure, jack up the bass on your equalizer. This rugged little speaker, which comes in five colors, is built to last.

» The bad: My one complaint: No volume control on the device, so if you want to adjust, you need your source nearby, unless you like to walk.

» Cost: $49

» Available from: divoomusa.com, powerful­power.com and amazon.com

Ross Werland, www.chicagotribune.com