Aeroport tuning confusion

[Triticum Agricolam]

I was really hoping to try out the aeroport but I may not be able to with this build. Now if you ran the 1 6" would

It sound bad? What's the cons to running a port too small? I'll have to completely redo all of my box specs now. I had it all hammered out for a 6" aero. I'll have to refigure for a slot. It's gonna have to be a rather large slot too.

What happens when you don't have enough port area is port velocity will get really high. This usually results in a lot of port noise which may or may not be noticeable in your system. You will also start to get a lot of port compression, which is the part that really sucks. Port compression causes the impedance to rise, cone excursion to increase, and output to decrease around the tuning frequency. Basically your ported box begins to act like a sealed box. It doesn't take much port compression at all to cost you 3 dB of output, which is like throwing half your amplifier power away. In extreme cases you can lose 10 dB or more.

[Brody57]

I was really hoping to try out the aeroport but I may not be able to with this build. Now if you ran the 1 6" would

It sound bad? What's the cons to running a port too small? I'll have to completely redo all of my box specs now. I had it all hammered out for a 6" aero. I'll have to refigure for a slot. It's gonna have to be a rather large slot too.

What happens when you don't have enough port area is port velocity will get really high. This usually results in a lot of port noise which may or may not be noticeable in your system. You will also start to get a lot of port compression, which is the part that really sucks. Port compression causes the impedance to rise, cone excursion to increase, and output to decrease around the tuning frequency. Basically your ported box begins to act like a sealed box. It doesn't take much port compression at all to cost you 3 dB of output, which is like throwing half your amplifier power away. In extreme cases you can lose 10 dB or more.

Okay so I know to get thw area of an aero you use pi times radius squared. But that only accounts for the diameter. Does the length of your port factor into the whole square inch thing? Because a 6" port would be 3.14 x (3)(3) = 28.26. That only accounts for the actual diameter of the port? That doesnt include how long the actual port is correct? Hopefully that makes sense haha.

[MrSkippyJ]

including length would be port volume.

[Triticum Agricolam]

Okay so I know to get thw area of an aero you use pi times radius squared. But that only accounts for the diameter. Does the length of your port factor into the whole square inch thing? Because a 6" port would be 3.14 x (3)(3) = 28.26. That only accounts for the actual diameter of the port? That doesnt include how long the actual port is correct? Hopefully that makes sense haha.

Port area is a two-dimensional measurement. Like you said, a 6" port has 28.26 sq in of area. When determining port area, port length is irrelevant. Where length comes into play is when determining what the tuning frequency will be and how much internal box volume the port will take up.

[Brody57]

Okay so I know to get thw area of an aero you use pi times radius squared. But that only accounts for the diameter. Does the length of your port factor into the whole square inch thing? Because a 6" port would be 3.14 x (3)(3) = 28.26. That only accounts for the actual diameter of the port? That doesnt include how long the actual port is correct? Hopefully that makes sense haha.

Port area is a two-dimensional measurement. Like you said, a 6" port has 28.26 sq in of area. When determining port area, port length is irrelevant. Where length comes into play is when determining what the tuning frequency will be and how much internal box volume the port will take up.

That makes sense. I appreciate the help! It definitely cleared up some things for me.

[Brody57]

Honestly I could run an 8" Aero and get close to what I would need. Running an 8" would give me 50.24 sq inches of port. Thats 10 square inches per cube.

[Triticum Agricolam]

Honestly I could run an 8" Aero and get close to what I would need. Running an 8" would give me 50.24 sq inches of port. Thats 10 square inches per cube.

No, that's not close to what you need. Forget "port area per cube" rules. They are based on assumptions that aren't always true, and definitely aren't true in your case.

[Triticum Agricolam]

I looked up the specs on your sub, here are some things to consider.

1. The recommended box size is 3.4 cu ft, you are wanting to exceed that by about 50%. You are also overpowering the sub. You will need to be careful you don't damage the sub from over-excursion. This sub doesn't have a very large Xmax and you are going to be exceeding it significantly. A properly set subsonic filter is a must.

2. The minimum port diameter that is acceptable IMHO is a 10" aero port. Once port velocity gets over 32 m/sec port compression can cost you 3 dB of output or more. That's like throwing half your amplifier power away. Ever with a 10" aero port I'm seeing port velocity around 36 m/sec. Real life doesn't always work out exactly like simulation says it will, but that's still cause for concern.

3. A 10" aero port will need to be about 27" long to tune 5 cu ft to 35 hz. You can have some of outside the box if the length is an issue. There are always slot ports too.

4. If you still aren't sure how much port area you want to run, design the box so you can change out the ports and experiment, it will be a lot easier than rebuilding the box three times until you get it right.

[Brody57]

I looked up the specs on your sub, here are some things to consider.

1. The recommended box size is 3.4 cu ft, you are wanting to exceed that by about 50%. You are also overpowering the sub. You will need to be careful you don't damage the sub from over-excursion. This sub doesn't have a very large Xmax and you are going to be exceeding it significantly. A properly set subsonic filter is a must.

2. The minimum port diameter that is acceptable IMHO is a 10" aero port. Once port velocity gets over 32 m/sec port compression can cost you 3 dB of output or more. That's like throwing half your amplifier power away. Ever with a 10" aero port I'm seeing port velocity around 36 m/sec. Real life doesn't always work out exactly like simulation says it will, but that's still cause for concern.

3. A 10" aero port will need to be about 27" long to tune 5 cu ft to 35 hz. You can have some of outside the box if the length is an issue. There are always slot ports too.

4. If you still aren't sure how much port area you want to run, design the box so you can change out the ports and experiment, it will be a lot easier than rebuilding the box three times until you get it right.

I had this sub custom built to take care of the xmax problem. They rebuilt pretty much the whole thing. It's built like a tank now. I honestly don't know how much this sub will take. It sure seems like it could take a lot more than the 3,000 RMS a stock one can take.