Another Port Question...

[MAG-nanimous]

I used sketchup to plot out a box design I want to build for my 3 12" kicker comps.

Kicker suggests 2.25 cubic feet per sub for a vented enclosure.

I used ExpoSports calculator and according to the suggested port dimensions from kicker it's tuned at around 41Hz.

I want to tune the port to 35Hz.

Again using ExpoSports calculator I was able to find at least four different port size variations to get me to or close to 35Hz.

H x W x L

1. 2 x 6 x 8.5

2. 1 x 12 x 9.3

3. 2 x 8 x 13.2

4. 4 x 4 x 11.8

What I want to know is which of these port sizes would be the best to use and maybe any other info I may need about port tuning. I'm leaning towards the 2 x 6 x 8.5 port but don't know what will cause port noise. Thanks in advance.

[Guest]

whats the dimensions of the box would be a good start

[MAG-nanimous]

whats the dimensions of the box would be a good start

Well it's going to be one single box but each sub will have it's own chamber and port.

The external dimensions of each chamber if they were seperate would be 17 x 13.5 x 22.5.

Hope that helps.

[Guest]

Well it's going to be one single box but each sub will have it's own chamber and port.

The external dimensions of each chamber if they were seperate would be 17 x 13.5 x 22.5.

Hope that helps.

itll be louder if they are all in one single chamber box

[MAG-nanimous]

itll be louder if they are all in one single chamber box

I'm not going for too much spl, just more spl over a sealed box.

In any case, I can always draw up an alternate design that has it in one chamber. Just delete some segments from the sketchup model.

But for now I would like to keep it as three chambers and ports.

[CR Boom]

#2 is a no,

I would sugest #1 or #4. But it is hard to say with out seeing the box..

[MAG-nanimous]

#2 is a no,

I would sugest #1 or #4. But it is hard to say with out seeing the box..

Here's the box. The missing board is where I plan on placing the ports. I plan on using the bottom board as part of the port wall. I was also playing with the idea of using the sidewalls of the box as part of the port wall.

But like I said, I'm still learning and not sure which part of the box to use as the port wall. I also have a design for a wedge box that's the same as this.

It's going into my magnum and I will be having subs fire up and the ports fire back.

[Guest]

2x10x20 would be sufficient as a port. theres enough port area, in which all of your port dimensions you gave are way way way too small

edit: but having a port like that will decrease the air space to 1.7cuft. but itll still be fine

edit 2: if you have a sedan, you would want the sub and ports firing towards the trunk, for SUV or hatchback, sub up and port back

Edited May 20, 2009 by Krannyman92

[MAG-nanimous]

2x10x20 would be sufficient as a port. theres enough port area, in which all of your port dimensions you gave are way way way too small

edit: but having a port like that will decrease the air space to 1.7cuft. but itll still be fine

That actually brings up one of my other questions that I have been having for awhile.

How exactly is the port area calculated for a slot port and what is a value that should be achieved relative to the size of the enclosure?

Thanks.

[Guest]

That actually brings up one of my other questions that I have been having for awhile.

How exactly is the port area calculated for a slot port and what is a value that should be achieved relative to the size of the enclosure?

Thanks.

port area is calculated by (for a slot port) multiplying the height and the width (not the depth). the general rule of thumb is that you want 14 to 16sqin of port area PER cubic foot of box space.

the Port Area Range in the calculator already does some of the calculations for you and tells you what the optimum port area size is for the box you "made". and the Port Area is what you have inputted to the calc for the port size.

Edited May 20, 2009 by Krannyman92