Inverted Sp4 18s Tuning?

[Subwoofer Stokes]

Building a box for 2 Sp4 18s. Dimensions are 58W x 24D x 24H. Box came out to be 16.5^3 ft. This is going in my c1500 ext cab. Subs will be inverted and port will be between the front seats. Was thinking of a port 12 x 6 but dont know what to tune to. I like low notes a lot but dont know what would sound good low. Any suggestions?

[Miguels]

that looks to me like not enough port area

[Miguels]

what power are you going to be throwing at them?

[Subwoofer Stokes]

Thinking 2 aq2200s

[Miguels]

i would get a crescendo bc5500 for both and thats the minimum at .5 ohm .. the sq2200 will just be tickling them.. a 7.5k would really push them and a 9.0k will push them to the limits

you also need to get the box bigger and give it more port area.. 58x28x24 with 210 square inches of port at 33hz with port on the diver side subs pointing up.. if the box is too big for you go with 15's.. there is no point on going with 18's in a small box with a tiny port

edit.. the tuning on the box depends on what you will be listening most of the time

[Subwoofer Stokes]

What about a 4th order? my max dimensions are 58w x 28d x 42h. I just thought about doing the first dimensions so i could invert the subs. I ultimately am looking for the best low notes.

[Subwoofer Stokes]

Or maybe 6th order? I dont know much about 4th or 6th order boxes. I've only most messed with ported and few sealed

[Miguels]

maybe if you wall it 5 cubic feet on the sealed and 10 on the ported or 15. its doable

[Subwoofer Stokes]

Now that sounds like something to think about!

[Miguels]

N8 says all extended cab c1500 should come with a wall from factory lol