hey guys i am looking to build a box here in the next few days and am having trouble finalizing a plan. my max dimensions are w-41 d-23 h-20. i have been messing around with the torres box calculator and cant get a design perfect...its not giving me the sizes for the cut sheet for the ports? an 18'' psi built sub will be going in it and tuned for all around daily listening but still hit the lows. i will be feeding it 1500rms for now and it is going in a 98 ford explorer sport. i would like to have the sub up and port back towards the hatch if possible. any insights guys? thanks.