51 speaker system series harman kardon hkts surface matt colour black transmission mode cable front speakercentresurround connection to av receiver number of speakers 6 components 4x satellite 1x centre 1x subwoofer 2x surround 2x front frequency response 45 20000 hz recommended amplifier power 10 80 impedance 8 ohm front speaker build type satellite speaker front speaker types 2 way magnetically shielded closed wall mountable front enclosures