Amazon.com: Pioneer TS-300S4 12" Car Subwoofer : Electronics
Audio Visual World - Pioneer TS300S4 - 30cm (12") 4Ω Single Coil D-Series Pioneer Champion Series PRO Subwoofer - Replacement for Pioneer TS-W3003D4 TS-W3002D4, and TS-W3001D4.
Used Pioneer PDP-S12 Subwoofers for Sale | HifiShark.com