Need Help With Aero Port

[Colby88]

Alright so I got like the slotted port down and how to make sure you use enough port area and everything but I'm confused on how to find port area in an aero port. The box I'm building is a 4.33 cubed box without displacement. 2 T0 12in rockford fosgates are going in this. The guy requested to use aero ports so idk anything about them really. Please help. Im starting from scratch really on the port.

[Wasteland_Audio]

The formula is 3.14 x (radius^2) or Pi (r^2). Example, for a 6 inch port you would do 3.14 (3^2) which is 28.27 inches of port area. Due to the efficiency of aero ports you can usually get away with using about 80% of the port area you would need for the same slot port. So if you needed 100 square inches for a slot port you could get away with about 80 - 85 inches using an aero port. For your situation 2 6 inch should be plenty.

[Colby88]

The formula is 3.14 x (radius^2) or Pi (r^2). Example, for a 6 inch port you would do 3.14 (3^2) which is 28.27 inches of port area. Due to the efficiency of aero ports you can usually get away with using about 80% of the port area you would need for the same slot port. So if you needed 100 square inches for a slot port you could get away with about 80 - 85 inches using an aero port. For your situation 2 6 inch should be plenty.

Well from reading up on a lot of stuff, people say that you want to use 8-10 sqin of port area for aero ports. Is that true?

[DLHgn]

Well from reading up on a lot of stuff, people say that you want to use 8-10 sqin of port area for aero ports. Is that true?

What do you mean by this? Do you mean by 8 - 10 in^2 per ft^3? If so, drop that idea. Ratios do not take into account other factors such as the amount of power being applied. To convert from the dimensions of a slot port to the equivalent diameter round port the equation is

2*SQRT((W*H)/PI)

Derived from:

W*H = (D/2)^2*PI where D/2 = Radius of a circle

You can simulate a round port in WinIsd to see the amount of port velocity you will get at a certain cross sectional area on a given amount of power. The general rule of thumb is to keep it below 30 m/s otherwise you will start to run into port noise (it could start even sooner than that). Luckily with the hard flares of an Aero port it takes a smaller amount of port area to create noise than a standard slot port or even PVC tube but honestly, I would just stick with an Aero that is close to the amount of area as your slot port *assuming you can fit it in the design and still have proper net box volume* edit.

[Jessica]

don't go by sq per cube rules, im over 14"^2 per with my aero and i still get chuffing at high volume near tuning.

[Colby88]

Well from reading up on a lot of stuff, people say that you want to use 8-10 sqin of port area for aero ports. Is that true?

What do you mean by this? Do you mean by 8 - 10 in^2 per ft^3? If so, drop that idea. Ratios do not take into account other factors such as the amount of power being applied. To convert from the dimensions of a slot port to the equivalent diameter round port the equation is

2*SQRT((W*H)/PI)

Derived from:

W*H = (D/2)^2*PI where D/2 = Radius of a circle

You can simulate a round port in WinIsd to see the amount of port velocity you will get at a certain cross sectional area on a given amount of power. The general rule of thumb is to keep it below 30 m/s otherwise you will start to run into port noise (it could start even sooner than that). Luckily with the hard flares of an Aero port it takes a smaller amount of port area to create noise than a standard slot port or even PVC tube but honestly, I would just stick with an Aero that is close to the amount of area as your slot port *assuming you can fit it in the design and still have proper net box volume* edit.

Ok well i seriously don't know math that well so help me out with what some of it means lol. space isn't the problem. so i can do whatever size port just confused on the steps.

[DLHgn]

Multiply the width of your port by the hight. Then divide that by PI (3.14). Then take the square root of that number. Then multiply it by two. That will give you the diameter need for your round port to have the equivalent area as the slot port.

Example:

Lets say your port is 14" W x 7" H

14 * 7 = 98

98 / 3.14 = ~31.21

SQRT(31.21) = ~5.59

2 * 5.59 = ~11.17

This says that a round port with a diameter of 11.17 will be equivalent (give or take a few decimals) to a 14" X 7" slot port. Round down or up to the nearest whole number which would be 11 in this case. Using an 11" round port will get you ~95 in^2 of port area. Pretty close. Sometimes you may have to round down too much and may have to round up. Use the equation as a guideline then choose the diameter that is the best choice for you (size availability and space availability).

[Colby88]

Multiply the width of your port by the hight. Then divide that by PI (3.14). Then take the square root of that number. Then multiply it by two. That will give you the diameter need for your round port to have the equivalent area as the slot port.

Example:

Lets say your port is 14" W x 7" H

14 * 7 = 98

98 / 3.14 = ~31.21

SQRT(31.21) = ~5.59

2 * 5.59 = ~11.17

This says that a round port with a diameter of 11.17 will be equivalent (give or take a few decimals) to a 14" X 7" slot port. Round down or up to the nearest whole number which would be 11 in this case. Using an 11" round port will get you ~95 in^2 of port area. Pretty close. Sometimes you may have to round down too much and may have to round up. Use the equation as a guideline then choose the diameter that is the best choice for you (size availability and space availability).

That makes a lot of since but how am i suppose to come up with that when there is no port. all i have right now is 4.33 cubed box without displacement. like how would i get "14 by 7" port when i don't have one? if that makes since, just little lost sorry lol.

[DLHgn]

Sorry, I assumed you already know what size port you wanted to use. It would probably be best just to use a simulation program. I know WinIsd is free and works well but can be a little tricky to learn at first. You will need to know what you want to be tuned at and go from there or play around with the tuning to see what works best for your situation and wants. Play around with the size of the port area and see what the velocity graph yields. Remember that the larger your port area is, the longer your port will need to be in order to achieve the same tuning and that a longer/larger port will take up more box volume thus changing the tuning.

[notorious97200]

You should get a design from someone.

It's simple maths.

You'll have to calculate port volume, add woofers displacement, then add the net volume (that you choose for your port length, port area was already ok) :That will give you the Gross volume of the box.

Good luck.