Okay.. I'm looking about about .0625 FT3

Here the diamentions
It's a bass tube

10" round

to make .0625 ft3 how long does it have to be?

I try'd and my match is not matching up.
I got 15 1/2 inches long.

But the calculate i get is .625 ft3
vol=Pie X Radias^2 X height then divide by 1728. It's getting .625 ft3... Need .0625
Is my formula wrong??

HELP....

 

You need a box that is 6/100th of a cu ft? Ok......
.0625 cu ft x 1728 cu in =108 cu in, and a 10" tube has a radius of 5" so 5 x 5 =25 x 3.1416 =78.54 sq in, so 108 cu in / 78.54 = 1.375095492 so the tube would be just under 1.5" long 5x5=25x3.1416=78.54x1.375095492=107.9999999/1728=.0624999999 cu ft
Maybe you should check what size of box you need again. 94

 

actually misprinted. I need .625 ft3
So is the formula V=pie x radias^2 x height then divide by 1728 to get ft3 ??
3.1416 x 25 x 14 = 1099.56 / 1728 = .636 ft3 ???

 

That sounds better, although you can get an exact length by changing your known volume, [.625cu ft to cu in] .625cu ft = 1080cu in, divide by area 78.54sq in and that would be 13.75".
Here is one more wrinkle, is .625cu ft gross or net volume, [does it include the displacement of the speaker? 94

 

It's net.
so 13.75 - 14 would be good enough?

 

Yes in a sealed enclosure, 10% up or down is no biggy, but if it's net volume you will need to add the displacement volume of the speaker to the .625cu ft, that will give you the gross volume. 94