Source speaker sub 8005-as 21 inch big power bass 3000w powered subwoofer on m.alibaba.com
RCF SUB-8005AS Single 21″Active High Power Subwoofer – Sonic Circus
One unit (not pair) |21 Inch Woofer for Bass Compensation of Open Baffle or Cabinet | W-21 - Lii Song (Lii Audio), unique speaker, amplfier, quality and cost-saving parts for HiFi DIY