Multiple Round Port Confusion..

[eliassami5]

So im tryin to design a box for an Fi BL 18 and i need two 6" round ports, so i plug in my numbers in this calc: http://www.carstereo.com/help/Articles.cfm?id=31, and it tells me that my port length should be 24.23 in long..does that mean each port has to be that long? Or does it mean that i divide that by two and make each port 12.xx long?

Here is the box so i dont really have that much room to have two 24" long ports going on in there, and a slot port would be really dificult with the back angled like it is. Any help would be cool thx.

I just drew the ports to be 12" long so you can get the idea of how much room there is in there, the box is 5.2cubes net and i wanna tune it to 32hz.

[eliassami5]

goin to sleep bump

[97maxima]

length=each

[Bunker]

You could go with 4 3" ports and it would be right at 12 and a 1/8" long and that's each.

Edited April 16, 2009 by Bunker

[Noobtastic14]

x5 thats each port.

or make the box bigger, my two 6" ports were ~12" @32hz but my box was 7cuft

-Drew

[Boon]

How much power do you have? A bigger box wouldn't hurt and would make the ports a much easier length.

[SplPhreak]

Well it looks to me like he's trying to fit a box in a tight space, hence the angle of it. So I doubt making the box larger would be an option

[eliassami5]

Well it looks to me like he's trying to fit a box in a tight space, hence the angle of it. So I doubt making the box larger would be an option

yup yup, its going behind the second row seat in my jeep Cherokee and i want to retain as much space as i can in the trunk area, i could make it much larger but i figured 5.2 cubes is just at the recommended specs. Would just using 1 6" port result in too much port noise?

Here is the same box but it's for 2 12's, the box for the 18" will be 2" less depth wise

Edited April 16, 2009 by eliassami5

[Boon]

yup yup, its going behind the second row seat in my jeep Cherokee and i want to retain as much space as i can in the trunk area, i could make it much larger but i figured 5.2 cubes is just at the recommended specs. Would just using 1 6" port result in too much port noise?

Here is the same box but it's for 2 12's, the box for the 18" will be 2" less depth wise

Hang on so you're going from 2 12's to an 18 and you're making the box smaller? That doesn't make much sense

IMO unless you have well over rated RMS power to the 18 you'll be choking it in a box that small, a 15 might be a better option given your constraints.

[eliassami5]

Hang on so you're going from 2 12's to an 18 and you're making the box smaller? That doesn't make much sense

IMO unless you have well over rated RMS power to the 18 you'll be choking it in a box that small, a 15 might be a better option given your constraints.

The box for the 2 12's was way oversized and it is a bit over 6 cubes, i figured i could make a more efficient box for the 18 and give it the minimum recommended space which is 5 cubes. And how would i be "chocking" it?...as in i dont have enough port area or as in the box dosent have enough air space? And it's only gonna be fed ~1000 watts RMS.

So ur saying more power = smaller box, and rms power = larger box?

Here is an update on the box..its 6.9 cubes tuned to 32 hz. Im worried about there not being enough space between the bottom of the ports and the bottom of the box..

Edited April 17, 2009 by eliassami5