Amazon.com: IMC Audio PPA8SS 8 Inch Car Speaker Box Enclosures - 8 Subwoofer Box for Great Sound Quality Home & Vehicle Car Speakers 8 Inch Speaker Terminal One 8" Sub Box - Charcoal : Electronics
Ported Dual 8" Subwoofer Enclosure - SSA STORE
MTX ThunderBox8 Single 8" bandpass subwoofer box at Crutchfield