5.25 Inch Subwoofer Speaker Driver 4 Ohm 30 W Home Theater Sound Audio Loudspeaker External Magnetic Woofer 1Pcs - Newegg.com
Celestion G12H 70th Anniversary 12 Inch 30-Watt 8 Ohm Speaker – Chicago Music Exchange
Vox AD-30C 30 Watt 10" Speaker Driver – NTC Tech
15 inch Subwoofer Replacement PRO DJ Speaker Sub Woofer Loudspeaker Wide Full Range Loud Aluminum Frame,2200W PMPO, 90oz Magnet, y-30 Grade Powerful Magnet 5 Core (15185 08 AL) - Walmart.com
ALT-20195 RV-SALPHA8 8 inch LoudSpeaker 1.5"V.C. | Kobe Trading Company, Inc.