Disco 4 ($100) is the first significant redesign in SuperTooth's Bluetooth speaker family since the Disco 2 in 2012. Instead of the hourglass-like shape of its predecessors, this one is shaped to look like a megaphone. Coming in a variety of colors, it has a rubber handle on top, enabling you to carry it around. The internal battery, rechargeable with the included micro-USB cable and wall adapter, is slated to last between three and twelve hours,…