Circle Port Help

[Guest]

im trying to do some math for my buddy mike (fibtlforlife). he's planning on making a 3.5cuft box tuned to 32hz and he wants to use aero's.

i got 50sqin of port area needed, and that turns out to be 4 4" ports, and a length of 34.87"

how do you make a port length that long? unless im doing something wrong.

Edited June 10, 2009 by Krannyman92

[FiBTLforlife]

the box is going to be 15'' in height and about 40'' long to work with for ports. box is really 56'' long but the sub is taking up that extra room.

was thinking about putting the ports out of the box some facing up if i could. which is what we are trying to figure out if i can do that with 15'' if height.

mike

[Decaf]

when using aeros you can 1/2 the needed port surface area because they are ~50%+ more efficient

so u really only need 3 4"

26.5 total length

1 6" aero might even be the most efficient since it has less surface area of port to create friction... its 28.27sqin... and might act more like 40-55sqin

17.8 total length

the ports come stock with a total length of 17..." anything more than that you have to use ur own center tube... or use a pvc elbow

[FiBTLforlife]

when u say total length is that for all of the ports combined or for each one..lol i know stupid question but ive never dont flared ports

[Decaf]

each port

[FiBTLforlife]

lol damn ok thanks man, time to sit down and think threw the box. i ordered a port already 4'' but its only 17'' long

[FiBTLforlife]

each port

is there any way i can take the 4'' ports and make it were they are 17'' long or less? if i use 4 4'' tubes would that work or no. not to sure on how the tube ports work

[Decaf]

if u used 4 4" aeros 17" long... aka the lowest tuning with 3.5cuft to work with

17.19" = 45hz tuning... so no... you need to use less port surface area to drop tuning or use elbows and new pvc pipe to get the correct length

which if u are using 4 4"... thats 36"

[Derrick824]

Use a single 6" aero.

[Airborne]

My box is 4 cubes and I use a single 6" aero for 2 12" Sexxx. Fu%$ing pounds too.