If the published specs are correct, the 10" box is too small. Make it an 11" cube and then you can use a 6" port. F3 should be ~35 Hz. Better yet, go for an EBS alignment of say 12.5"^3 and a 6" port for an F3 of ~28.You might also ask why PE show SPL@300 watts for a driver specified @ Pe=150w.
Bob