Help with some math: Volume

[werty]

Ok so I designed this sub enclosure for my truck last December...and I've even made more and sold to customers. But I'm not sure how to calulate the volume because of the angle involved ...can someone tell me the exact volume of each separate box and total for both.

There are 2 boxes connected by a frontal board....the frontal board both holds the rear speakers and amp in place.

I included some pics of the finished install as well as the dimensions for whoever can do the math.

Thanks mucho!

EDIT: I used 7/16 thickness for the wood

[Sweeney921]

The problem the angle presents pales in comparison to taking in account the 7/16" thickness. I'll calculate it

[my porsche]

for a triangle multiply the average of the bases times the height and length.

so, 6X12X17.5, but since you used 7/16th you have to take that into account, so subtract that from all raw measurements and you get inside measurements of 11.125" X 5.125" X 16.625" for a total interior volume of 947.88 cubic inches.

a cubic foot is 1728 cubic inches, so about 0.55 cubic feet per box.

if you make them as big as you possibly can you'll get a deeper sound. (not sure if this is as big as possible.) but most sub woofers have a recommended enclosure size of close to 1 cubic foot.

hopefully my math is right, you can double check just to make sure.


EDIT: and what did you use to carpet those boxes? i just ended up painting mine the color of my carpet because I didn't want to make it look shitty, but now to fit my new subs I have to get the rear seat raised a few inches, and they'll make me a custom box relatively cheaply, so i dont have to build more boxes.

[werty]

well your math seems right...but you mentioned "triangle"...and its not a triangle design...the top of the box dosent come to a point...but rather 2 points...with 4 sides

so did you take this into account?

I got the carpet from Checker Auto...and used spray adhedsive and a staple gun

[Sweeney921]

1.1439 cubic feet for the 2 enclosures together, but I'm probably off by a few tenths.

EDIT: Either MP sucks at math, or I suck at math. I took into account the flat top part and separated the side into a rectangle and a triangle, added up their areas, then multiplied by the depth, then by 2 because there's 2 enclosures. Either way they're very small....my Q-Logic is 1 cubic foot exactly, for 1 subwoofer.

[werty]

1.1439 cubic feet for the 2 enclosures together, but I'm probably off by a few tenths.

that sounds about right too

[werty]

yea I know they are small...I've got a regular cab truck and I'm using every spare inch for the box

recommended for my subs is .7 cubic feet and a max of 1 cubic foot for a sealed box like mine

so if you guys are right, my box is either .55 or .57 cubic feet...aka not quite enough

however I must say the entire cab rumbles very nicely, back massage and everything...I love it

EDIT: i still think you and mp might be wrong though...i think your taking out the back 3 inches of my box in your calculations

[Sweeney921]

i think your taking out the back 3 inches of my box in your calculations

No I made sure I added that part.

[werty]

No I made sure I added that part.

hmmm. I guess your right then....Thanks for the help!



If anyone thinks they can get a more precise measurement, please do tell

[kingofthering]

Split into 2 seperate pieces - a triangle and a rectangle and calculate the volumes of each, then add.

[drakkie]

Split into 2 seperate pieces - a triangle and a rectangle and calculate the volumes of each, then add.

Exactly. The volume of the triangle is offcourse:

(0.5 x width x height) x depth.

(0.5 x 6 x 12) x 50 = 1800 cubic inches

The rectangle is offcourse:

lenght x width x depth

Because of the gap (which I assume runs through to the bottom of the box) you will get:

length x width x (depth - depth of the gap)

12 x 3 x (50 - 15) = 1260 cubic inches

Triangle + rectangle sections are (1800 + 1260) = 3060 cubic inches.

Or you make a 1 minute 3D-CAD drawing and have the programme calculate it quickly. But that's for the lazy

[my porsche]

Triangle + rectangle sections are (1800 + 1260) = 3060 cubic inches.

Ok so, sweeney, Mr. Anal, the difference between ours is 0.02...but drakkie is of course very very wrong. Theres no way they can be 2 cubic feet.

[Sweeney921]

Ok so, sweeney, Mr. Anal, the difference between ours is 0.02

wow take a chill pill

[werty]

Or you make a 1 minute 3D-CAD drawing and have the programme calculate it quickly. But that's for the lazy

So your saying its 1 cubic foot per sub then? maybe you can do the 3d cad for me...pretty please. That would be helpful for my little business.

[my porsche]

wow take a chill pill

im not angry i just thought it was funny how you assumed one of us sucks at math over 0.02 cubic feet.

werty...haven't you learned not to trust drakkie? his answer is completely wrong, while sweeney's and mine are right.