Bluetooth speaker portable speaker outdoor speaker power rating 25 watt speaker system 20 stereo principle active frequency response 60 20000 hz crossover frequency 5200 hz power supply rechargeable battery battery life 30 h functions streaming smartphone charger controllable via buttons control features bluetooth pairing onoff volume control number of tweeters 2 treble chassis 19 mm tweeter material tweeter tissue number of subwoofers 1 bas