All you mathmaticians(sp) need some help

[killed300ex]

im going to make myself a sub box for my truck i took measurements and came up witha size i need. What i need to know is how much air will be inside the box. the box will be 60inchs long 8 inch wide at the bottom 3 inchs wide at the top will have a back 13 inchs long and the front plate wil be 14 inchs long. there will also be a divider in the middle. All of the wood il be using it 3/4 inch think including the divider. I need to know how many cf of air space will be in this box. I came up with 2.06cubic feet. I would like someone to check this for me it would be a big help thanks
killed

[killed300ex]

just a hint i need the inside air space not including the space to wood takes up if you follow what im saying i need the space inside the wood.
killed

[LTandRaptorider]

Ummm... just a second...

Dammit! I knocked my glass of whiskey over reaching for the calculator... :eek2:

[killed300ex]

lol

[K2Snow]

I got 1.58 cubic feet. I used this site to do the calculations http://www.radiomods.co.nz/speakerboxcalc.html

Height: Compensated for the wood being 3/4 inch thick, that is top and bottom. Therefore, I subtracted 1.5 (which is 3/4 multiplied by 2) from 13 (which is the height of the box, the back part) So I put in 11.5 for height.

Width: I decided to split the problem in two, and get the value for one side, and then multiply that by two to get the total. So, 60/2 is 30. The divider is 3/4 inch thick, but we are cutting the box in half. So 3/4 divided by 2 is 0.375. Subtract that from 30, and we get 29.625. Remember, that is for half of the box.

Depth: Used the equation at the top of the page in the case that you have a wedge shaped box (which you do). Using that equation, you end up getting a value of 4 for the depth.

With all of that filled in, just hit the button that says "How Big?" next to cubic inches, and there ya go. You should get a value of 0.7886284722222222. Remember, this is the cubic feet for half of the box. Simply multiply by 2 to get the cubic feet value of the entire box. 0.7886284722222222 * 2 = 1.5772569444444444. Rounded off to the nearest tenth, your box is 1.58 cubic feet without the speaker put in. At the bottom of the page I linked above, it has the option to add in speaker displacement in case you need to do that. Hope this helps.

[hondafox440]

Height = 13 - 1.5 (width of boards, .75 + .75 = 1.5) = 11.5

Depth = 8+3 (base 1 + base 2) = 11 / 2 = 5.5 - 1.5 (width of boards) = 4

Width = 60 - 1.5 (width of boards) = 58.5 - .75 (divider) = 57.75

11.5" x 4" x 57.5" = 2645" / 1728 (1 cubic foot in inches) = 1.5306712962962962 cubic feet.

Are you building a sealed, ported, or bandpass box? Remember to get the volume as close to the recommended as you can. I recently built a sealed box with a friend, and we were within cubic inches of the recommended volume, and used the formula .7x depth, .7x height, and 1.4x width. It sounds awesome.