The Beosound Explore portable Bluetooth speaker from Bang & Olufsen is built to last, with a rubberized base, aluminum body and internal design that protects against drops and falls. It is dust- and water-resistant and has True 360 sound with a dual full-range driver and heavy base. Listen for up to 27 hours on a battery charge. Amplifier: 2 x 30W Class D full range; Frequency response: 56–22.7Hz.