Amplifier Double Channel with Subwoofer TPA3116D2 2X50W +100W
Amazon.co.jp: XY-T50H TPA3116D2 2x50W Bluetooth 5.0 Subwoofer Amplifier Board 2.0 Channel High Power Audio Stereo AUX USB Base AMP : Industrial & Scientific
ZK-MT21 2x50W+100W 2.1 Channel BT5.0 AUX Digital Power Subwoofer Amplifier Board | eBay