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Calculating port area with xmax?


shanesauce

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If you read the directions above the calculator it says the box for minimum diameter is for round Ports and the box for minimum area is for square Ports. That means it's not saying that the round Ports have to have at least that amount of port. It just has meet the minimum diameter.

Aero Ports are more efficient and don't need as much port area to be effective.

t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

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Yup the X area will count towards the internal volume. I think your design looks pretty good, nice job.

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The sub closer to the port might have issues, in general it.us better to have the subs the same amount of distance from the port opening inside the box.

I can't say for sure or not but hopefully someone with more exp can help out.

t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

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Oh and round the edges of the port, better air flow.

t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

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It should work fine, I had a box similar to that and had some issues but one sub was roughly 4" from the port opening

t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

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Share on other sites

If you read the directions above the calculator it says the box for minimum diameter is for round Ports and the box for minimum area is for square Ports. That means it's not saying that the round Ports have to have at least that amount of port. It just has meet the minimum diameter.

Aero Ports are more efficient and don't need as much port area to be effective.

I assume you used this calculator?

http://www.carstereo.com/help/Articles.cfm?id=31

Yes, the aeroports do need that much port area. If you convert the minimum diameter of the port that it gives you into the area, you will find that it is the exact same amount of port (less than 0.075 sq inch rounding error from a test I did). Remember the formula for the area of a circle? Its A = pi*(r^2)

And aero ports are not more efficient. A port is a port as long as it has enough area for the subwoofer(s). It doesn't matter if the port is an aero, slot, or even if it is shaped like an octagon, or a star, or a triangle, or an oval, or _______ (insert shape here). What is necessary however is that the port width stays consistent throughout. Barely anyone makes odd shaped ports though because it takes up more room to do that, and it is more simple to just do a slot port.

I was planning on 45's for the corners, this the only design I can mock up without aero ports that keeps the subs as far from the port as possible.

45's are a good idea, as well as sanding the corners of the port, just enough to take off the sharp edge. Your design that you sketched out looks good, but Torres calculator is inaccurate, when I plug in 1.2cu ft, 28sq in port, and 56 port length into WinISD it says that this box is actually tuned to 32.21 hertz. If the port area stays at 28 and the internal volume stays at 1.2 cu feet, then it would take a port length of 65" to get you to 30.05 Hz. Problem is if you increase your port length you wont have 1.2 cu feet anymore.

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Aero port that are flared have better air flow then a typical slot port which in turn reduces the chance of port noise. That makes them more efficient at reducing port noise and getting good airflow.

A lot of people don't sand/paint slot Ports to make them smooth. The rough edges and walls make for a.more restrictive path then a smooth wall.

I've read a few threads on this forum to where it has been said and explained by some skilled members that aero Ports do have a tendency to be.more efficient. Because of their smooth walls and ability to prevent port noise they don't require as much port area to be effective.

t1500bdcp

2 t2d4 15"

1 t600.4

1 t400.2

1 set p1 tweets

singer alt, tons of wiring, smd vm-1, 80prs, back seat delete, still in the works, aiming for a 145-147 with the ability to play 25hz up to 50hz.

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so for my box, which is 2 CF, I will need 8" aero port which needs to be 56" long. That make no sense at all. (using the calculator)

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