Converting a one slot port into a two?

[James Bang 5,000+ posts]

Let's say I use one of moe's plan, that has lets say a 30" port length. Can I take that port length and cut it by 2 resulting in two 15" long ports. Would that work?

-James

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[matt_martin87 10+ year member]

Sorry. That doesn't quite work that way. You essentially get double the port area, so length is going to have to increase in order to keep tuning the same. I believe that, now I may be wrong, length would approx. double.

 

[James Bang 5,000+ posts]

man... only if it was that simple.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[thai_creeper 10+ year member]

**** that shits confusing

 

[dleccord 5,000+ posts]

oh so what is the formula?

 

[James Bang 5,000+ posts]

oh so what is the formula?

i dunno. I just thought that a 2 slot port would be sexy.

 

[matt_martin87 10+ year member]

Well, if you're dead set on having two ports, you could always divide the port area on each port.

Lets say your port calls for 30sq inches. Hypotheticly(sp), you start with a port 3"W x 10"H at a length of 20". In order to keep the same length per port, you would have to do a pair of ports at 1.5"W x 10"H, each with a length of 20". I am almost positive this is how you could do it.

PM a box designer like PV Audio or Moe Lester if this is all too confusing for you still. They know more than me.

 

[James Bang 5,000+ posts]

Thanks for the reply,

but. hmmm? isn't that just about the same as my theory of dividing the length by 2 but keeping the same width. wouldnt' that allow for the port area?

 

[vetkilr 10+ year member]

Nooooooooooooooo.

IE:

7cuft box

Port 5"X10" 20" length is tuned for 28hz.

Now go with 2 ports 5"x10" and shorten the length to 10" and now its tuned for 50 hz..............

Length corresonds to port area(for a tune feq.)the more area(bigger/more ports) the longer the runner needs to be(port length).

 

[Trixter 10+ year member]

splitting a port into two will lengthen your ports.

you could...

-divide your box volume by 2

-figure out the length of each port

-make the box with demnsions to account for the total port (and sub) displacement.

if you want your box to have an even look to it, you can just put the port in the middle of the subs. if you move the port from the wall of the box to the center, don't forget to add 1/2 of the port's width to its length. when the box is designed to have the port sharing an wall with the box, port correction come into play...which is simply taking 1/2 of the port's width off the end of the port, so moving to the center you will need to replace that 1/2 width to the length.

 

[lionel2 10+ year member]

My box is about 38" wide with 2 15" slot ports...not sure how they did it...but it works...it looks cool and sounds great..and adds stability

 

[James Bang 5,000+ posts]

My box is about 38" wide with 2 15" slot ports...not sure how they did it...but it works...it looks cool and sounds great..and adds stability

share some pix bud

 

[iamamp3pimp 5,000+ posts]

what you can do is cut down on each port size. lets say your box is calling for a port that is 4x12 inches (48 sqin)

you can make 2 12x2 inch ports there fore resulting in 48 sqin of port.

but you wil have to take into accound the airspace taken up by the additional wood from the port walls, and ad that into the equation as well, but personally, there is not that much difference.

 

[Trixter 10+ year member]

what you can do is cut down on each port size. lets say your box is calling for a port that is 4x12 inches (48 sqin)
you can make 2 12x2 inch ports there fore resulting in 48 sqin of port.

but you wil have to take into accound the airspace taken up by the additional wood from the port walls, and ad that into the equation as well, but personally, there is not that much difference.

yes, you can, but you will need to re-calculate because the port length will be different, it will end up longer...that's where i was going with this in my previous post. simply splitting 1 port's area equally into 2 ports will not create the same tuning freq. because the length will need to be changed as well.

My box is about 38" wide with 2 15" slot ports...not sure how they did it...but it works...it looks cool and sounds great..and adds stability

the box was designed to have 2 ports.