Bluetooth speaker portable speaker power rating 41 watt system 2 way system speaker system 20 stereo principle active crossover frequency 4200 hz amplifier type digital power supply mains operation colour beige housing material mdf enclosure function streaming control features bass level control volume control high channel control bluetooth pairing design front firing subwoofer number of tweeters 2 treble chassis 19 mm number of subwoofers 1 b