5 CORE 8" Full Range Subwoofer Car Audio Speakers, RMS 50W Peak 500W, 4 Ohm Car Vehicle Audio Full Range Drivers, Wide Range DIY Loudspeaker Woofer Replacement WF 890 DBL - Walmart.com
Data East Subwoofer Only Kit SW-3VA - Pinballpro.com
Amazon.com: PRV AUDIO 6MB200 v2 6.5 Inch Speakers Midbass Woofer 8 Ohm, 100 Watts RMS, 200 Watts Program Power, 93.5 dB 1.5 in Voice Coil for Small Custom Enclosures Pro Car Audio System (Single) : Musical Instruments