American Audio ELS15 BT is a lightweight, multi-functional 15-inch Active Speaker featuring Bluetooth and a built-in MP3 player. Users can play music from Bluetooth enable mobile devices such as mobile phones and tablets with the use of running connector cables. Users can also utilize the microphone inputs (XLR and ¼-inch Jack) and the built-in MP3 player with USB and SD Card inputs. The ELS15 BT has an extremely high efficient design, low power consumption, and plenty of output power ideal for small and mid-size events. It also has a built-in Bi-amp system: one amp powering the Titanium Driver and one amp for 15" woofer with 33 oz magnet.