Features: 1) Max. power: 400 W 2) Sensitivity: 90 dB 3) Impedance: 4 ohm 4) Frequency response: 20Hz - 18KHz Description: 1) This function can satisfy your hearing character: crazy disc or appreciate symphony\'\'s super woofer as your will 2) This function restrict each channel\'\'s signal scope, prevent extra scope, effectively protect your costly speaker unit, it is properly settled the contradiction of stronger input and the speaker\'\'s used period