SMAKN TDA2030A 2.1 Stereo Audio Amplifier 3 Channel Subwoofer Bass Amplifier Board The main channel: TDA2030A X 2; Power: 18W + 18W; horn with 4-6 inches, 4-8 Euro 15-50W full-range speakers.New versions of colors and knobs may change Welcome to contact us Subwoofer: TDA2030A X 1; Power: 30W; recommended to use 4-8-inch, 4-8 Euro 20-60W subwoofer. Voltage: AC 12V; 30W 2A power transformer above. Output Impedance: 4-16 ohms. Cable: motherboard and pitch plate with 30CM long 6P cable connection.