Amazon.com: Q Power Q Bomb Series 12 Inch Ported Car Subwoofer Sub Box Enclosure with Single Vented Chamber Design and Black Bed Rhino Liner Spray Finish, Black : Everything Else
Car Audio Dual 12" Vented Subwoofer Stereo Sub Box Ported Enclosure Speaker - Walmart.com
How to Design a Ported Subwoofer Box : 8 Steps - Instructables