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View Full Version : Porting this box....Help

solidcrowd
08-08-2007, 07:10 PM
How would i port this box and what would i need?

http://i187.photobucket.com/albums/x247/solidcrowd/box.jpg

Thankz

phyphoestilic
08-08-2007, 07:15 PM
a port.

solidcrowd
08-08-2007, 07:50 PM
yea how do i figure out how long or how wide of one to get

Trixter
08-09-2007, 01:39 PM
yea how do i figure out how long or how wide of one to get

generally you need about 12sq" of port area for every cu'...so in your case you looking at about 55sq" of port. if you went with precision ports (flared) you could do like 3 4" ports.

use the formula in my sig to find the length for you desired tuning.

if your going to use round ports, divide you box by the number of ports your going to use and plug the numbers in. this length will be for each port.

if your going to use precision ports, do the same as i said above but subtract an additional 5" and cut you center piece to this length.

solidcrowd
08-09-2007, 05:31 PM
generally you need about 12sq" of port area for every cu'...so in your case you looking at about 55sq" of port. if you went with precision ports (flared) you could do like 3 4" ports.

use the formula in my sig to find the length for you desired tuning.

if your going to use round ports, divide you box by the number of ports your going to use and plug the numbers in. this length will be for each port.

if your going to use precision ports, do the same as i said above but subtract an additional 5" and cut you center piece to this length.

Is this the same formula? http://www.the12volt.com/caraudio/boxcalcs.asp#por

Trixter
08-10-2007, 01:25 PM
i guess so....they break down the numbers more though but you should get the same result. just remember, if the box is already built, you need to find the port length, then use that to find the port's displacement (L x W x x H make sure to count the wood that makes the port as well[don't count the 3/4" for the front of the box and if the port and box share a wall, don't count the thickness of that wall either. this was counted for by using internal measurements]). once you have the port's volume, subtract this from you initial Vb and do the calculation again. this will be your port length.

if the port shares a wall with the box an end correction factor will be needed. this is simply adding 1/2 the port's width to it length. (take this into consideration with finding the port's displacement as mentioned above.)