Power Output : R/L: 21W + 21W RMS Noise level : 25dB(A) Frequency response : 55Hz~20KHz Microphone dynamic range : -50~30dBV Input sensitivity : PC: 700±50mV AUX: 550±50mV Bluetooth: 550±50mFFs Input type : 1/4”, AUX, PC, Bluetooth Midrange & bass unit : 4 inch (116mm) Treble unit : 1/2 inch (13mm) Bluetooth version : V4.0, A2DP and AVRCP protocol