This is a custom ported enclosure made previously for a customer. I can make you a similar enclosure to this, please just let me know!

This one is very close to Audio Frogs recommended enclosure for their 12" GB series  subwoofer.

Enclosure will be about 1.5 cubic feet after subwoofer and port displacement, tuned to 33hz as audiofrog calls for in the manual. 

External Dimensions: 34.5" wide, 14" tall, 12" deep.
Port: 2" x 11.5" tall approx 32" long for 33hz target

This enclosure will be carpeted in the medium charcoal gray color, port inside will be black in color. Enclosure comes with terminal places (two) wired on one side of the enclosure (opposite side of port) so each coil of the subwoofer can be wired per terminal. I will include 12awg ofc speaker wire and ring terminals to fit the enclosure.