help with box design for rockford p3 12

[Scalian]

I have a rockford p3 12 in a 1 cu ft sealed box currently with 500watts rms to it. I want to build a ported box and try that out. Looking at the specs it calls for a 1.79 cu ft box tuned at 40hz. It is going in a 09 altima that is my daily driver and the goal is litening to music. I listen to all types of music from rock to rap. Is it best to just stay with the 1.79 and 40hz tuning or is there a better set up. Did some playing around and i think a box about 14H x 12D x 30.5W will get me to those specs. Looking for some advice as this will be my first custom box build. Hoping maybe someone has played with this sub before.

[bcbrassard]

Listen to Joe X, he knows his shit when it comes to boxes. 40 hz is to high though.

[Scalian]

Thanks for the reply to the thread i started. Would you have a suggestion of what to tune to. I know there isnt a perfect tune that cover every kind of music but is there some happy medium that is commonly used.

[Joe X]

34-35Hz will let you reach enough of the low end you need for rap and the likes.

[Scalian]

I used winisd to figure out the port lenth tuned at 34 hertz and sketched a drawing up. Does this look correct. The port is 2" x 12.5" x 29.25 measured down the middle for length. Is centering the sub the correct thing todo or shoud it be shifted one way or another? Thanks for the help so far just trying to learn

[SMF93]

I don't know if the enclosure is correct, but if it is infact tuned to 24 Hz that is too low.

[Scalian]

34 hz tune, late night typo

[Joe X]

Your box is 1.6 cubes [email protected] with 25 square inches of port area, I'd go for at least 1.8 net.

[Scalian]

I reran some numbers.

Port is 25 in^2 by 28" in length. according to winisd it should tune to 34.06 hz

Internal box volume dimensions 10.5 x 12.5 x 32.5

Woofer displacment of .106 ft^3

If i did my math correctly after port and woofer volume i should end up with 1.8.

Figured the port at 12.5 x 2.75 x 28 I added the .75 to the 2 in port opening to take into account the .75 mdf making up the port. I think this is the correct way.

Port comes out to be .559 ft^3

Displcement on sub is .106 ft^3

Desired net box volume is 1.8 ft^3

Add those up end up with 2.465 ft^3 gross

I know the hieght and depth i want so adjusted the length to get the gross volume i needed. Internal dimensons of 10.5 deep x 12.5 high x 32.5 wide.

Does this math look correct?

If so ill draw up another box.

[Joe X]

From the above I take you are doing 14x34x12, port 12.5x2x28:

Your box is 1.83 cubes [email protected] with 25 square inches of port area.

The disagreement on tuning can be explained partly due to the end correction for slot ports with common walls which WinISD don't account for.