Port walls?

[Caleb9107 10+ year member]

If I need more port length than the first two port walls? Can I add a third wall or is this a terrible idea? Also, what is the minimum width my port needs to be?

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[mlstrass 5,000+ posts]

I'm pretty sure you need to either offer up a drawing or reword your questions with more info about the enclosure and no one has any idea what you're asking....

 

[Caleb9107 10+ year member]

Well it's a slot port first off. It has the initial port wall running straight back, makes a 90 and this is the second port wall. I am asking can it make another 90 and have a third port wall? I'll try to load up my drawing real fast..

 

[ascitiesburn69 10+ year member]

Yes you can. Add 45's in all corners. And the minimum width of your port depends on the size of your box.

 

[Caleb9107 10+ year member]

This is the prelim drawing. And what factors of the box size controlls port width?

 

[Caleb9107 10+ year member]

Bump.

 

[KyleBechtold 5,000+ posts]

you understand that port wall 2 lowers your tuning correct? why do you need more port wall what are you trying to achieve?

 

[KyleBechtold 5,000+ posts]

port width is an option to gain more port area if the box is wider than it is deep..

 

[PioneerSPL1990 10+ year member]

Port length kills deebeez man.

 

[Caleb9107 10+ year member]

Well I want to tune it to around 34 and as it is with two walls it is at 38. I'm not gonna compete so that isn't too big of an issue for gaining every db. Any ideas on what will help? The net space is about 2.09 cu ft with 30 in of port at 1.5 in width.

 

[DNick454 10+ year member]

It looks like you have separate chambers for two subs? Is it 2 cubes total or per sub? 1.5" wide of a port is kind of skinny too. The port is like 12" tall, that only yields 18 sq. in of port area for 2 cubic feet, (9 per cube, rule of thumb is 12-16 sq in of port area per cube)

 

[Caleb9107 10+ year member]

Its gonna be two seperate chambers for two subs. The port is 30 in long and the box is 19 high (17.5 internals). By calculating area (LxW), shouldn't it be 30x1.5 yielding 45 sq in of port. And each chamber is 2.09 cu ft. Is my math off on the port area by that much?

 

[DNick454 10+ year member]

Its gonna be two seperate chambers for two subs. The port is 30 in long and the box is 19 high (17.5 internals). By calculating area (LxW), shouldn't it be 30x1.5 yielding 45 sq in of port. And each chamber is 2.09 cu ft. Is my math off on the port area by that much?

Yeah, you don't get port area by multiplying it by the actual length of the port's path. It's cross-sectional area. How tall the port is by how wide is port area. The bigger the port area is, the LONGER it actually has to be to achieve the same tuning. But, you can't have it too small in port area or it will be like breathing through a straw and the air velocity coming out of the port will be excessive and you will get turbulence and port noise.

1.5" wide X 17.5" tall = 26.25 sq in of port area. 26.25 sq in divided by 2 cubes = 13 sq in per cubic foot of net volume which is actually ok.

 

[Caleb9107 10+ year member]

So what would you suggest to get a lower tuning? I believe 38 is too high? Am I correct in thinking this? My goal was about 34 hz. This is a daily driver that I would just like to hit the lows.. I am not aiming for any numbers or competing in any way.

 

[Caleb9107 10+ year member]

Bump for the night.