I just built a custom sub enclosure in my wheel well w/fiberglass, so its a weird shape and i cant really measure it w/a ruler or anything. my subs require .7 - 1 cubic foot per sub. so how can i convert cubic feet to a measurement in water? if i dont have enough space im gonna use some poly fill. is there a conversion for how much poly fill will make the sub "think" its in a bigger box? thanks.
-Jan

 

Take the inside measuements of a plastic box, then fill it with water and empty it into the box you built for the wheelwell this will give you the amount of airspace you have.

 

i cant find a plastic box, do you know how many cubic feet a gallon of water is?

 

Water and your MDF baffle really don't mix, and all you will end up doing is making a mess....here;s what I always do:

Go get a bunch of packing peanuts (enough to fill the sub enclosure completely) and a medium sized cardboard box (~1 cubic foot). Fill your sub enclosure to the top with the packing peanuts....don't crush them in there, just make sure you fill it completely.

Then measure your cardboard box and find out it's volume. Fill the box with the packing peanuts from the sub enclosure until completely full...then dump them out and start over....repeat until the sub enclosure is empty. Count the number of boxes it takes to remove all of the peanuts from the enclosure (measure out the last batch as it probably won't be exact).

While this method isn't the most accurate, it's definitely not as messy as pouring water into your box. With a sealed enclosure, the "peanut method" will provide the level of accuracy necessary.

 

that was a good idea, thanks. I just did it and i have the perfect size enclosure. now i can finish my false floor system setup.

 

if you build a fiberglass box and it is too big, what can you put on the inside to lowere the amount of air inside? would wood blocks work? or is there something better?

 

For future reference, there are 28.32 liters in a cubic foot.

 

wood blocks would work fine....anything that is non-porous would work fine, so long as you could secure it to the enclosure properly.

 

For weird fiberglass shapes, ive also seen people take a strong bag (or mutliple bags in eachother), stuff it in the box, and then fill it with water.

Then pump it out, or take it out by other means (a cup!) and measure )

-Rage (who likes the rcurly method)

 

lol ok in my early installing days i tried that trick but years later and many fiberglass gallons later and by accident i filled an old sub but with paking peanuts i think the box had to be like 1 cubic foot or something i then dummeped it into the fiberglass shell i was working with all i did was move the peanuts around with my two mdf side baffles marked it ,screwed and glassed the sides made the baffle and i was done works every time ant here is VERY little mess also jut a hint i would line the bottom of the box with this stuff call gorrilla hair its a fiberglass mat and bondo mixter you can buy ant any auto body suppy place it will save you many coats of resin and glass just make sure your mold stays in the car so it dosnet loose its shape