I'm putting 2 Dc lvl4 12s in my trunk, inverted, firing towards the back of the trunk. I will have at least half the seat down most of the time and will take out the speakers in the rear deck. I'm thinking about building 2 boxes like this:
Box Width: 19.5
Box Height: 17
Wood Thickness: .75
Square Port Width: 1.75
Square Port Length 2 : 8
Volume: 1.796 ft^3
Square Port Area: 27.125
Tuned Frequency: 37.99
This is what I used to come up with that: RE Enclosure Calculator
I know 1.5ft^3 is the recommended box volume but The tuning frequency was too high at that volume while keeping 18 in^2 of port area per ft^3 of box volume.
What do you guys think? Too big of a box?