But he has 4.3ft^3 total to work with, so after displacements he's looking at a really long 8" port in order to get a 35hz tuning, which will drop his internal volume down quite a bit. Right now it looks like it ends up being 3.35ft^3 with a 28" long flared 8" port in order to get a 35hz tune.48 inches of port is perfect for a btl in 4.3 cubes. 11 inches per cube