The Sound Town Class-D plate amplifier enables you to build your own powered subwoofer cabinet. The STPA21-710 power amp is equipped with 2 XLR-1/4” combo inputs and 2 XLR (through) outputs. It handles formidable 1000W continuous at 4-ohm, 500W continuous at 8-ohm power. Each of the speaker output generates 500W continuous at 4-ohm, 250W continuous at 8-ohm and allows you to connect two passive PA speakers with the amp. The plate amplifier also comes with master volume control, Low Pass Filter (LPF) adjustment and a polarity switch.