1. ## Ported box help

OK I used the AJDesigner software to determine the information I need in order to build a ported box, but I have a few questions about the outputted information.

OK I put in my T/S parameters for the Kicker 0512L704 I have and the information that was outputted was:

Vb = 3.655 ft^3 // ok I understand this, volume not including displacement of the sub or port

Fb = 32.2Hz // tuning frequency of the box I'm assuming

F3 = 27.3442Hz // roll-off frequency of the system

but here's where I get confused....

Lp = 5.76385 in. // I want a slotted port box, and this is the length of the port, but how do I determine the L shape dimensions for the port?

Port volume = 70.1674in^3 // meaning that is the l*w*h of the port, but how do I incorporate this into the box?

...............

Where is a good link I could go to in order to manually build a system because I cannot choose a specific tuning frequency using this software, and I would like the freedom to do so.

2. ## Re: Ported box help

Have you checked this site?
http://www.accelerator-pedal.com/ported-box.asp

This link was reccomended by Mustangowner.

3. ## Re: Ported box help

Originally Posted by docutech
Have you checked this site?
http://www.accelerator-pedal.com/ported-box.asp

This link was reccomended by Mustangowner.
That's a **** cool site, but I have one question.

How do I obtain the flattest bass response for a ported box? Find the volume for a sealed box that provides the flattest bass response (qtc = .707), or do I have to use a different set of equations?

4. ## Re: Ported box help

I dont believe that is an option with a ported box. A sealed enclosure will give you a flat response...

Custom nclosure gurus may have to help us out on this one...

5. ## Re: Ported box help

i agree i love that site!

6. ## Re: Ported box help

Originally Posted by docutech
I dont believe that is an option with a ported box. A sealed enclosure will give you a flat response...

Custom nclosure gurus may have to help us out on this one...
i aint no guru, but i tink i can answer that hehe, you CAN get a flat response out of a ported box, just not as flat as a sealed.

just tune it lower, 28 ish. go too low and you get boomy.

7. ## Re: Ported box help

OK so it is the tuning frequency that ultimately determines how flat the curve is in the bass range, right?

8. ## Re: Ported box help

Originally Posted by 96civ
OK so it is the tuning frequency that ultimately determines how flat the curve is in the bass range, right?
cha, pretty much. see if you tune it to 32 hz, youll see a GIANT hump in that certain area of the freq range. lets say you tune it to 28 (which is tougher to hear than 30-35), the hump will be on the 28 hz area and boost that range while the rest 28 and up will be i guess pretty much flat?

and the tuning to 28 will also boost the tougher to hear freq's. so its a per say

9. ## Re: Ported box help

OK I've manually setup a system, but I'm not sure if it's right. Also I don't know how to construct the port pieces.

In the Kicker manual the street bass setup for my driver is: 2.5ft^3 + port displacement; 2.5" x 13.25" port

Port length:
Av = 33.125in^2
Vb = 2.5ft^3
Fb = 31Hz
Lv = (Av * 1.84x10^8)/(Vb*1728*(Fb/.159)^2) - .823sqrt(Av)

Lv = 32.379" and I've estimated it to 32.375" for easy cutting
__________________________________________________ _______________
Displacement of the port:
Dp = ((W+T)*H*D)/1728
W = 2.5
H = 13.25
D = 31(5/8)"
T = .75"

Dp = .788ft^3
__________________________________________________ _______________
Driver displacement = 0.078ft^3 = Ddp
Thus
Vb + Dp + Ddp = Net volume

2.5 + .788 + .078 = 3.366ft^3
__________________________________________________ _______________
Box construction:

3.366 * 1728 = 5816.448

Internal:
W = 23.5"
H = 13.25"
D = 18.6875 (estimated for cutting purposes)

External:
W = 25"
H = 14.75"
D = 20.1875"

Tuning frequency: 31Hz
Port width: 2.5"
Port area: 33.125in^2
Port length: 32.375"

What I need to know are the dimensions of the pieces the make up the port.... or for lack of better words, the two pieces that make up the L shape.

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