BOSS Audio Systems R1100M Riot Series Car Audio Subwoofer Amplifier - 1100 High Output, Monoblock, Class A/B, 2/4 Ohm Stable, Low/High Level Inputs, Low Pass Crossover, Mosfet Power Supply, Stereo : Everything Else
Amazon.com: Fosi Audio ZK-TB21 Bluetooth 5.0 Stereo Audio Receiver Amplifier Board 2.1Channel Mini Wireless Digital AUX Amp Module Bass and Treble Control for Home Passive Speakers Subwoofer TPA3116D2 50Wx2+100W : Electronics
How To Connect A Subwoofer To An Old Amplifier Or Vintage Receiver