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CalSpecBoy
01-06-2004, 06:25 PM
Ok I was thinking about maybe building a box for my 2 subs but the biggest question for me is this

"Im bad with math but how do you find the volume of a box so that I know the box I build has the right amount. Is there a simple formula? Also do angles matter? Say i wanted a box like this shape /_| and not just |_| shaped would the formula still work. I ask the shape part becuase I have 2 12's and a ext cab ranger so seating room and spare room for box is a tuffy."

Also thanks in advanced!!!

esco
01-06-2004, 07:34 PM
u multiply depth by height by width and divide by 1728....
for example
my box is gonna be 12x18x36...which is 4.5^ft, 2 chambers, so 2.25^ft per chamber
so then i divide by 1728 after multiplying those 3 numbers together and thats the volume(in cubic feet) of my box
but thats for a rectangular box, i dunno bout the slanted truck box style

CalSpecBoy
01-06-2004, 07:50 PM
ok cool thanks atleast its a start and a very good one indeed!

CalSpecBoy
01-06-2004, 07:52 PM
height is top to bottom. width is side to side. so depth is front to back?

Trixter
01-06-2004, 07:59 PM
"Im bad with math but how do you find the volume of a box so that I know the box I build has the right amount. Is there a simple formula?

L x W x H / 1728 = Total volume - when you measure this use internal dimensions to get the internal volume. If your using 3/4 wood, then just measure the outside of the box and subtract 1.5 from L, H, and W. (.75+.75=1.5....get it..)

Also do angles matter? Say i wanted a box like this shape /_| and not just |_| shaped would the formula still work. I

To find the volume of an angled box you need to divide it into two parts first. You will end up with a square and a triangle. Take the box below. The top is 5". Subtract the top from the bottom and you get 4. the bottom of thebox has two numbers now, 5 and 4. Take the 5 and you get a box that is 5" wide and 13" tall. now do you L x H x W / 1728 to get the volume of this one. Now the formula to find the volume of a triangle is L x W x H / 2 / 1728. So 4" wide and 13" tall (and whatever long) and divide it in half and then divide it 1728.

If the box below is 15" long then...

Box A: 5 x 13 x 15 / 1728 = .56cu'
Box B: 4 x 13 x 15 / 2 / 1728 = .23cu'
Box A + Box B = .79cu'

Hope this helps.

Trixter
01-06-2004, 08:00 PM
height is top to bottom. width is side to side. so depth is front to back?

Shouldn't really matter as long as you know which is which.

CalSpecBoy
01-06-2004, 08:11 PM
Well not only does it make sense thanks to the graphic and elaborate explanations but I got a nice headace too lol thanks guys Ill keep this info and get around to making it as soon as the weather is in the 50's atleast. I cant do garage got a dodge dakota and a 68 mustang taking up my space =) so Ill let ya know after awhile.

esco
01-06-2004, 08:18 PM
good luck bro, im just startin to build my box this weekend, its been hot as balls all year long, i dont think it went below 60 at all...i live in florida :)

CalSpecBoy
01-06-2004, 08:34 PM
thanks man, count your self lucky one day we had 50's by that same night we touched down at 2 degrees...jesus...F*ing weather...sometimes Kansas isnt worth it.

sumone
01-07-2004, 02:08 AM
you could do what trixter wrote or just get the area of the trapezoid (the face) and multiply by [depth|height|width]

going of the top of the dome but I think it was something like h*0.5(a+b), where a and b are the uneven lengths of the face and h is the height. get that and multiple it by the depth.

yukon_85
04-15-2004, 01:24 AM
i need an amp to push 1 audiobahn 15 its holds 800 watts can you hook me up

Trixter
04-15-2004, 01:44 PM
i need an amp to push 1 audiobahn 15 its holds 800 watts can you hook me up

Check the classifide section.

ngsm13
04-15-2004, 02:00 PM
An easier way for the angled box, since it's a trapezoid, would be to use the trapezoid formula.
Look at the side of the box /_| take the top width+the bottom width. No divide by 2. Multiply by the Height looking from the side. Look at front, multiply by width.
Get that number, divide by 1728 and ur done. SO...
.5 x (top width+bottom width) x height x total width in front = BLAH divide by 1728....woohoo done. peace

NG

just makes sense as one big step...MIGHT help ya. peace

NG