Need helping with box tuning

[RageQuitForLife]

I just need some help with understanding how to tune the box to a specific frequency

if my box is 36Wx22Dx16H which would make it 5.9 cubes and i want to tune the box to 30hz what do i have to do?

I went on a few websites that calculate the port length, but when i put in my numbers my port length didnt make sense.

For the port calculator i put the port would be 4 inch wide and 16 inches tall, and came out as a port length that is 25.7 inches long.

I want to make a middle port between the subs, is the calculator using a side port and that is why my number is too big???

Please help i don't know what is wrong? thanks

[wil]

Maybe this will help you out, maybe I'm just wrong. But I would use Torres to tune your box:

(Somebody let me know if I'm wrong)

[hondakid1996]

The port halves as it bends with a center port box. So each chamber would only get a 2 inch wide port. That's if you go with Wil's design.