JBL GX Series 12" Single-Voice-Coil 4-Ohm Subwoofer Black GX1200 - Best Buy
JBL GTO1202D 12 inch 1200 Watts subwoofer - GTO1202D from JBL
Amazon.com: JBL Club WS1200 12" Shallow Mount subwoofer w/SSI (Selectable Smart Impedance) Switch from 2 to 4 ohm Bundled with Alphasonik Earbuds : Electronics