this pic is the 28hz port it is 6.25in tall, 30in wide, 35in deep.but only 15in of it goes into box. it is shaped like a L, when i remove the 28hz port it becomes a normal sub up port back box tuned to 43hz port is [7.75in tall, 31.5in wide, 11in deep. 43hz port has 8in from back hatch to breath.
internal box volume before sub and port displacements is 17.8, outer mesurements are 23in tall, 45in wide, 36in deep. double baffle, dowel bracing