Make the box 35" wide x 22" tall x 13" deep. Use two 4" diameter ports that are 5-1/2" long. Use 3/4" or 18mm Baltic Birch or MDF. Brace well using cross-braces (front-to-back and side-to-side) on each side of the woofer along the 35" dimension. The braces can be made using scrap cut from the panels.
The dimension 35wx22tallx13deep is inner volume ??
And i also can use these dimensions too
30 wide
20 tall
20 deep
?? m i right