slot port vs round port

[jday240]

I was given an Audiobahn sub recently and I am in the process of designing a box for it. I am a big fan of sealed enclosures but thought I'd give a ported box a try. At Audiobahns website in the tech support section they have a conversion from round to slotted port. My question is this- If the port is round say 4" X 7" deep and the slot port is calculated at 9 sq in. Does the slot port have a depth or is it just a slot cut into the box that measures 9 sq in ?

Thanks for your help. And yes, I know Audiobahn doesn't have the best rep but it was free and worth a shot.

-John

[jr_ss]

Each speaker will give you specs of say what the port size should be for a given air volume. Say you have a 12in speaker that you are building a 1cubic ft of airspace for, the speaker specs call for a 15.5in long x 3 dia. port. Each speaker is different and sometimes boxes built can't take the entire port size lenght.

Rule of thumb small airspace and no room for full port size, sealed box. Large airspace ported box.

[jday240]

Thanks for the reply, but I understand that. I was curious about a slot port design for my next box. Audiobahn's website doesn't specify if the slot port box is simply a slot cut into the face of the box or if it has a depth into the box. If anyone cares to look at Audiobahn's site under technical assistance there is a slot port converter (calculator).

jr_ss thanks again for the reply.

-John

[jr_ss]

I wouldn't just cut a slot, build a port if you want the slot. Bevel the edges as well so air flows in and out freely.

[jday240]

I will continue to research the issue, thanks for the reply.

BTW, your car looks great.

[PoorManQ45]

I take it by the fact that you're looking to use a slotted port that you are trying to minimize port noise, correct?

There's a much easier way.FLared ports! http://www.partsexpress.com/pe...8-350

[Looneybomber]

My question is this- If the port is round say 4" X 7" deep and the slot port is calculated at 9 sq in, does the slot port have a depth or is it just a slot cut into the box that measures 9 sq in ?

Yes it has a depth, but I can't remember the formula to for adjusting the length of the port in relation to the diameter. Anyway a 4" round port has an area of 12.56"^2. To keep everything the same, use a square port with an area of 12.5"^2 (6.25"x2") and use 7" as your length. Don't forget to bevel the edges of wood around both ends of that port. If your port was bigger, the length would also have to be longer and visa versa for a smaller port.