21 speaker system wireless speaker system series onkyo envision cinema surface matt transmission modes wireless subwoofer cable wireless connections spdif toslink 35mm jack line in bluetooth front speakercentresurround connection to av receiver number of speakers 3 components amplifier 2x front 1x subwoofer overall performance 90 watt frequency response 40 20000 hz impedance 4 8 ohm front speaker build type satellite speaker front speaker typ