ive tried 3 different ones so far and ive got 3 different results using the same dimensions.

all i need is .89 cu ft

Ported? Sealed? Space trying to fit it?

1 cuft = 1728 cu inches

multiply the internal dimensions by each other length x width x height and you will have cu in all you have to do is then divide by 1728: LxWxH=CuIn/1728 = Cuft

sealed, and it has to be under 38" wide and 16" tall

38-1.5 = 36.5

16-1.5 = 14.5

36.5*14.5 = 529.25

.89 * 1728 = 1538

1538/529.25 = 2.9" (+1.5) 4.4"

Obviously you need to make it either less wide or less tall otherwise your box is on 3" deep on the inside.

The 1.5" assumes that you use 3/4"mdf for all of the walls.

i'm sure that makes perfect sense, just not to me

http://aneonrider.com/Misc%20Files/Enclosu...alculations.xls

it looks like thats for ported enclosures only

a box with external dimensions of 14" x 14" x 11.375" will give you ~0.89 cubic feet (using 3/4" MDF)

thats weird, the box wizard on rockfordfosgate.com and elementaldesigns.com or completely different with those dimensions, im so confused

You have to pay attention to whether or not the calculator is giving you internal or external dimensions...

Perhaps a quick review of 6th grade algebra is necessary. If you can't do some math none of them are going to work out right.

it looks like thats for ported enclosures only

You need to learn how to use Excel... click on the SEALED tab.

Use the square/rect calculator here:

http://www.the12volt.com/caraudio/boxcalcs.asp#wed2