Bluetooth speaker wifi speaker series panasonic all power rating 40 watt system 2 way system speaker system 20 stereo principle active amplifier type digital power supply mains operation colour black front colour black functions streaming dual speaker pairing control feature bluetooth pairing design front firing subwoofer speaker enclosure bass reflex number of tweeters 2 treble chassis 25 mm number of subwoofers 2 bass chassis 80 mm analog