If your using a round port, the 2" port is your problem, the lound noise that sounds like an air leak is port noise, the subs are only about 6" deep ypu should have plenty of room behind them, you need a bigger port, at a least a 4" port
using a round port 6-10 square inches of port area is what you want
A 2 cubic foot box needs between 12 and 20 square inches of port
a 2" port as 3 square inches port port area
a 4" port has a port area of 12 square inches and would be a much better choice