Box for Alpine 1542D

[BlackCivicHatch]

Equipment:

1 Alpine Type-R 1542D (15" dual 4Ohm coils)

1 Alpine MRP-M1000D (1000Wrms @ 2Ohms)

1 Honda Civic hatchback :

Now:

The current box is about 2.5 cu ft and tuned at about 40Hz

I'm content with the current sound, I just know that there's more in my equipment than I'm getting. When playing the Low lows, you can feel a "breeze" of air coming from the sub, but you cant hear (feel) it as much as expected. And with the current 3" diameter port, I have terrible port noise at these low frequencies.

Goal:

More Low frequency SPL. No port noise.

Alpine says 2.25 net internal with 22.5" port area, But I was thinking closer to 3cu ft net with 44" of port area....

I know most box builders don't like to deviate anymore than 10% from manufacturers specs, but for my particular goal, does this seem ok??