DD Audio - "Overall Digital Designs has developed a winner of a pre-built sub here." Read the full review by Australian Magazine "In Car Entertainment". Read now: http://goo.gl/cXcG6h | Facebook
2) DD AUDIO 1108-D4 8" USA MADE WOOFER 800W DUAL 4-OHM SUBWOOFERS BASS SPEAKERS | eBay
DD Audio Digital Designs 1508D-D4 8" 2400W Dual 4-Ohm Subwoofer
DD 608 Redline 8" subwoofer - Up close and personal - YouTube
LE-M08d: 250w to 500w - 8 Inch Loaded Enclosure - DD Audio
DD Audio Digital Designs 8 Inch 600 Watt Hi-Def Tuned Shallow Subwoofe — Big Jeff Online Inc
DD Audio Digital Designs 1108-D4 8" 800W Dual 4-Ohm Subwoofer