2 x JBL JRX218S 18" Passive Subwoofer Speaker | Reverb
The Best High-Performance Subwoofer | Reviews by Wirecutter
Amazon.com: Pyle Pro Line Array PA Speaker System - 2600W P.M.P.O 3-Way Full Range Loudspeaker Set, Wireless Bluetooth, USB/SD, 5-Band Graphic EQ, (2) 12" Active & Passive Subwoofer, (8) 4" Woofer, (4)