Porting this custom box

[Alex K 10+ year member]

Here's my box I designed for 4 12" cvrs.

Specs:

Each side is 5.61 cubic feet. Theres 2 sides

Now that I have the main box designed, could ANYONE give me advice on how to port a box shaped in that manner? I'm looking to port out the bottom with an L port. Squares are easy to calc the port, but on the polygon I have, I'm not familiar enough with how I would go about doing that. Sorry for any confusion and if anyone needs anymore specs, let me know.

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[Alex K 10+ year member]

someone has to know

 

[the Answer 10+ year member]

Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators

use the slot port calculator on ^^^ and it will tell u how long to make the port. if u need more help let me know.

 

[bubbagumper6 5,000+ posts]

It's going to be tough to put a port in along the bottom since the sides taper in, you'd be better off putting the ports vertically in the center of front (right where the two chambers come together)

 

[Alex K 10+ year member]

I got rid of the middle, and got ahold of that port calc. I have 11.37 cubic feet of airspace, and with the calc I put in:

Height 4 inches

Width 11 inches

Depth 4.1 inches

That'll tune it to 33 hrz

Now I know I probably did it wrong, so let me know where I goofed.

Here's a picture

 

[bubbagumper6 5,000+ posts]

That's NOWHERE near enough port area for that large of a box. You want like 12-16 square inches per cube of space. Right now you have 44 square inches (4*11) which comes out to be about 4 sq. in. per cube.

That port should be more like 8" x 20" x (whatever the depth needs to be to achieve desired tuning)

 

[Alex K 10+ year member]

This is throwing me off. You think if I handed you the dimensions you could plug them in the right slot for me?

Dimensions

13 cubic ft box without ports/brace/subs etc.

Depth - 38 inches

Width back - 31 inches

Width front - 48 inches

Height - 15 inches

 

[bubbagumper6 5,000+ posts]

This is throwing me off. You think if I handed you the dimensions you could plug them in the right slot for me?
Dimensions

13 cubic ft box without ports/brace/subs etc.

Depth - 38 inches

Width back - 31 inches

Width front - 48 inches

Height - 15 inches

If I get some time later, I will, but it's not that difficult. You just need to remember to keep in my mind how much port area you have. Decide on that, then punch the numbers into the calculator. The tricky part is that when your working with set dimensions, the port takes away from the total net volume, thus affecting the tuning. You have to play with the numbers a bit and accept the fact that your not going to get 33.00000hz, it will probably be like 32.6hz or something like that, and you'll just have to accept that, lol.