4th order for X12v2 help.

[Charlie Buffalo]

Looking into building a 4th order for my 2 X12v2's. Looking for SQL, right now my plans are 2.25cu ft sealed and 4.5cu ft ported, tuning at 48hz for a wider bandwidth (aiming for 25-70hz). I have 9.5cu ft after displacement to work with if anyone has a better suggestion. I mostly listen to EDM, rap, alternative and occasionally decaf. 

Thanks. 

[Joe X]

What's the vehicle?

[Charlie Buffalo]

2004 Jeep Liberty 

[Joe X]

The box specs you post result in the following estimated frequency response.

 

 

In reality that big peak will be softer than shown but the point is that it will not be the flat response you may be looking for.