box builders i need a little advice


Silver Member
Username: Cwruck

Post Number: 429
Registered: Feb-10
ok so i am making a new system for my car. it is 4 12" subs in a ported box. for power i will be more than likely using a soundstream rub1.2500d 2500 watts rms at 1 ohm. each sub is single 4 ohm so i can end up with a 1 ohm load.
ok now here's where im slightly confused.
for my box my width is 37 inches. height is 23 inches. and depth is 26 inches. but it will be a double baffle on the top so height will drop to 22.25 inches and i will be using .75 mdf all the way around
each sub im guessing has a displacement of .19
so that is ending up at 9.684 cu ft. now thats great.
also all the subs will be facing up firing at the roof. and for the port i want it at the bottom of the box firing at the trunk. make sense?
ok so for the port i am thinking of 4 inches high. 35.5 inches wide and around 24 inches for depth (thats for the tuning)
now with that i believe i am around 142 sq inches of port total, or maybe a little more, but not too worried
with the sub displacement of those dimensions, im ending up around 7.712 cu ft total. so around 1.9 cu ft per sub
now when im trying to figure out how much sq in of port to use. i am doing this. 9.684 x 14.5 and getting around 142. then dividing by 35.5 and ending up with 4. or close to 4
so that means my height should be 4 inches, since i used 35.5 as my width? is that right? and then the 24 just gives me a tuning of 34 hz.

is that the right way to calculate the port area?
if so thats great, i have been building boxes right this whole time. but if not, what am i doing wrong?

Bronze Member
Username: Makinblak

Monroe/Monticello, La/Ar

Post Number: 71
Registered: Oct-10
You need a hug...

Silver Member
Username: Cwruck

Post Number: 433
Registered: Feb-10
haha i got one earlier from my girl.
i know this all looks confusing, and i tried to explain it as simple as possible.
maybe to make it easier. how do you figure out how much port to have?
i know you want between 12-16 sq in of port per cube to minimize port noise
so is it total cu ft (like as if the box was sealed) x 12-16 and divided by the height to find the width needed
or in my case i am using the width to figure the height
im almost sure im right, but i could be wrong

Bronze Member
Username: Makinblak

Monroe/Monticello, La/Ar

Post Number: 74
Registered: Oct-10
I was alluding to huggington, who helped me with my box. I found the RE port calculator to be helpful.

Silver Member
Username: Canaanwhite

Monroe, Louisiana USA

Post Number: 229
Registered: Nov-10
Id do 6 12's

Platinum Member
Username: Insearchofbass

2 hifonics 2607s, 2dcSounds12xls SPL\idmax12SQ

Post Number: 15819
Registered: Jun-04
x2 for cone area
« Previous Thread | Next Thread »


Shop Related Deals


Main Forums

Today's Posts

Forum Help

Follow Us