Calculating Port Length and Tuning Using 2 Aeros

[The_Grimy_One]

Ok,
So I am pretty confused... I am trying to design my box for my 2 10s. Gonna be running 2 3" Aeros (Looking for some, let me know if you have some for sale). I am using the 12 volt calculator, but it doesnt seem to allow for more than 1 round port. So how do I figure out what length to make the 2? I am looking for a final box size of 2.4 @ 30 Hz.

[The_Grimy_One]

Ok, I found a site that will do multiple aeros. Now I am thinking I may need 2 4". My next question is, do you calculate port length with the box volume before displacement, or after?

[Imtjnotu]

After displacement and 2 4 " sounds a little big for 2 10's but don't quote me

Google psp port