JBL EON718S 1500-watt 18-inch Powered PA Subwoofer | Sweetwater
One unit (not pair) |15 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-15 - Lii Song (Lii Audio), unique speaker, amplfier, quality and cost-saving parts for HiFi DIY
What Is a Subwoofer? How Bass-Focused Speakers Work