Audio Visual World - JBL S21224 - Series II 12" component loudspeaker with switchable 2- or 4-ohm impedance
JBL Club 12 - Club Series 12" Car Bass Subwoofer 1100 Watts Bass Woofer BNIB | eBay
JBL Stage 122D - Subwoofer Car - 1000 Watt Harman Kardon Car HiFi Sound System Bass Box with Dual 4-OHM Coil - 30 cm | 12 Inch Bass Box, Black : Amazon.co.uk: Electronics & Photo