i am trying to make a ported box for my alpine type r (1042d) i need the box to be about 14" high, 5.5 top depth, 7.5 bottom depth, and somewhere around 33in wide (i think 42 if i move my rear speakers) the sub is invert mounted in between my 60/40 bench seats now.
anyone know how i can make the port/slot on this to make it somewhere around 38hz?

additional info
i got a kac 8152d amp running 550w. not sure what the settings are on the amp currently but has isosonic filter set to 15hz. has adjustable frequencies 40-200hz (or something close to that) and a MA audio high performance bass driver which amplifies the signal input. Alpine CDE 9874 amp wired with 8awg and amp to sub is 12awg

any help would be nice
thanks

 

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i have seen this thanks for the post. is it best to port it on the side? i heard port it in the front along the bottom

 

I guess it depends how you have your box facing, I did mine like that and my port faces the front of my truck.

 

might help if i put it in the fact its a regular cab... so its a slanted box with the slant in the front