Bad Box?

[Da64u 10+ year member]

for my type r's i just used that calculator and got

1.87225 - is this internal volume? and net is after sub is subtracted right?

these are manufactorers specs..

13.0" x 13.0" x 12.5"

internal volume : 0.85 ft cubed

net internal volume: 0.78 ft cubed

F3, Qtc : 49Hz, 0.7

i have to times internal manufact specs times 2 since its for 2 sub woofers right? that equals 1.7 so then what do i do subtract brace? its .75 mdf.

if you cant walk me through the steps could i give you deminsions of my 2 twelve box sealed and you tell me if it is good for my 12's?

btw. im really trying here lol

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[maldecido33 10+ year member]

if the manufacturer lists the internal volume, why would you try and calculate it yourself.

Just do (13.0-1.5)*(13.0-1.5)*(12.5-1.5)

the 1.5 you subtract is to account for the thickness of the wood (.75" on either side of the enclosure; .75+.75=1.5)

So,

= (13.0-1.5)*(13.0-1.5)*(12.5-1.5)

= (11.5)*(11.5)*(11)

= 1454.75 cubic inches

To convert to cubic feet:

= 1454.75 / 1728

= 0.842 cubic feet

A 12" Type R has a displacement volume of 0.071 cubic feet. I'm assuming this box only holds one Subwoofer as the dimensions wouldn't allow for two. So, we subtract 0.071 from our gross volume of 0.842 to get our net volume.

0.842 - 0.071 = 0.771 cubic feet NET VOLUME

Now if you have two of these enclosures, one per sub, you would have a total of 0.771 + 0.771 which equals 1.542 cubic feet.

This is the proper size for only one 12" subwoofer; I'd really look into a custom built ported enclosure by one of the designer's on here. Look at BJ Fisher's work; I recommend him.