Edifier R1010BT-B 2.0 Blurtooth Bookshelf Speaker (Black) Active bookshelf speaker system with 24W RMS power output, Bluetooth V4.0, pairs with two Bluetooth devices simultaneously, built in 100 percent MDF wooden enclosures, 4 inch bass driver and 13mm diaphragm tweeter driver. Dual stereo Line-in ports, treble upgrade on port A. Power output: R/L: 12W+12W. Frequency response: 70Hz-20KHz.