need help building my first box

[ChrisB4]

Alright, I have been into car audio for about a year,but want to have a better louder setup. The single 12" prefab box with 1200 watts that I have now is not cutting it anymore so i want to build my own box. So I used the torres calculator only to get stuck after the box demnsions. I dont know how to get the demensions of the port or how to tune it. I listen to all types of music so I think a box tuned to 35-38hz would be fine. Also I heard the box will vary depending on the air space of the cabin . I want a standard rectangle box with a single port off to one side of the box. My max trunk space is 21"L x38"W x 20"H.

My car is a 1999 Saab 9-5 3.0 V6 turbo and is a sports car so I am only want to use 2 of the 3 subwoofers I bought to save alittle weight.The equipment I will be using are 2of3 12'' D4 MMATS professinal audio , Porcast series subwoofers 700watts rms (NOT to be confused with juggernaut or dreadnaut MMATS) and 1 hifonics brutus BRZ 1200.1d (only until I upgrade to the 2400.1d). I Will be running 1/0 wire with a second battery in the trunk.

I tried a local car audio shop only for them to tell me a custom built box starts at $350 and I told them I would be back to pick up some power wire but thats not happening.

Also, how do you use screws and bolts as terminals? I've seen people do this on this site and would like to do it for my box, is it as simple as drilling the holes putting the screws and bolts in the sealing it from the inside. If I cant do that then I could just run the speaker wire through the port right?

Can someone help me on this I know were to get the wood and supplies, I have the tools to cut the hole for the subwoofers, I would just like some input from people who have done this before.

Thanks in advance everyone!