My enclosure specs are 36 wide 18 tall and 30 deep. According to the12volt.com this should be a lil over 9ft³. I want a 33 Hz tuned port I'm still undicided between 4 by 16.5inch port with a 11 inch length or 5 by 16.5 inch with 14 inch length. I'm more in question about the lengths. Are they accurate?

........oh k

The lengths listed on the12volt is with effective length added on so that must be taken into account.

Personally, I hate this port shit now. Ive made it too complicated in my head and gave up on the engineering part. Im a much better fabricator.

i don't understand is that me adding on to the box? Because i already have everything precut all i have to do is assemble cut holes and tunes port.

i don't understand is that me adding on to the box? Because i already have everything precut all i have to do is assemble cut holes and tunes port.

Read this tutorial on ports. It should help you to understand. JL Audio

Do I really have to make an L shape port to get the tune I want?

You only have to make it L-shaped if it does not fit within the depth of your box.

Oh OK I'm slowly understanding this now I'm just trying to keep my screw ups to a bare minimum

use aero ports from psp-inc. They have a calculator

use aero ports from psp-inc. They have a calculator

If using aero ports, what category does the k factor fall into? The value for two flanged ends, 0.85?

My port is in the middle of box. Do I still need do end correction factor?

BUMP

My port is in the middle of box. Do I still need do end correction factor?

BUMP

Maybe, maybe not. Depends on the length of the port and the depth of the box. If it long enough you have to add a bend at the back of the box, then you have now created a slot port (one side of the port becomes the rear wall of the box, which extends beyond the end of the port). If not, calculate it like a standard port.

Rum bum bum bum bump...... Well okay what is this Effective Length VS Physical Length? I've been reading this JL Audio article over and over.

Physical length = How long the port is physically, ie how long is measured down the center of the port to where the board ends.

Effective length = How long the port acts when it is in use. Because of the way a slot port is made using 3 walls of the enclosure, air "sticks" to the walls before dispersing making the port appear longer to the enclosure.

Physical length = How long the port is physically, ie how long is measured down the center of the port to where the board ends.

Effective length = How long the port acts when it is in use. Because of the way a slot port is made using 3 walls of the enclosure, air "sticks" to the walls before dispersing making the port appear longer to the enclosure.

I have start on a new box now. My new box is going to be 7.08 cuft. 39" width 16" height 24" Depth. Minus the port area, displacements, and bracing I should still be a little over 6 cuft. I'm using WinISD to calculate my port this time around. It's telling my length is 17.71(5" width by 14.5" height). So I'm asking if I should cut a board that length and call it a day?

Bump (sorry if I'm bumping too much I just want to get this box made by this weekend)

BUMP

Stop bumping your thread unless some actual time passes, by giving your post a day or two to be seen not a few hours. Be patient.