LAB OEM-Spec™ 2.75 ft^3 Ported MDF Subwofer Enclosure Box for Single JL Audio 15W0v3 Sub Woofer
GP Audio 6.5” Ported MDF Subwoofer Enclosure Single 6.5" Ported 3/4" (0.30 cubic ft) Tru Spec Series Subwoofer Enclosure (Made in the USA) - Walmart.com
Custom Ported Sub Enclosure Box for 1 15" American Bass XFL - 4.0 CU FT - 38 Hz | eBay
How to build a subwoofer box
Rockville RSST12 Single 12" 0.9 cu.ft. Sealed Car/Truck Shallow Sub Enclosure