But I really want to know how you guys tell how you figure out all the things you guys seem to know about your boxes.

Like how many cubic feet it has (I just forgot the formula I know its easy) and how you determine what your port hz is set to and things like that.

Never really checked on my box.

Thanks

 

(Length X Width X Height)/1728 = cubic ft

 

Dam I couldnt figure out what I was doing wrong when i was getting such a high as number. Had no idea about the 1728. Thanks

Now how can I tell what my port is tuned to?

 

How's your Algebra? The tuning frequency is a function of the port diameter, port length and the volume of the box.

To get the tuning frequency, you'll need the following info - all in inches:

R - radius of port
Lv - length of port
Vb - volume of box (in cubic inches)

Next, calculate the following:

1. 14630000xRsquared)/Lv
2. 1.463xR

Add answer 1 to answer 2 and divide the total by the box volume. Now take the square root of your answer and that should be your tuning frequency.

If you want an easier method, use the port calculator from this link and just plug in numbers until you find the answer.

http://www.the12volt.com/caraudio/boxcalcs.asp#por

 

Thats a perfect answer but I think its gonna be hard to do that myself.

What exactly is the radius of the port? There square

 

The radius is half the diameter. To get the diameter, measure across the port opening from one side to another. It might be a little tricky if the port has a flared end.

Is this a prefab box or a custom made piece? Are looking to build one for a specific subwoofer? What sub do you have?