Port Area Question

[1990RANGER 10+ year member]

Is it bad to have a port area thats larger than the calculated "minimum usable vent area"?

Cause on the box I'm designing, I need a minimum vent area of 21.69 inch^2, but is there like a maximum measurment you shouldnt pass?

Click to read more...

 

[cjjackson85 5,000+ posts]

Yes.

 

[g30ffr3y 10+ year member]

Is it bad to have a port size thats larger than the calculated "minimum usable vent area"?
Cause on the box I'm designing, I need a minimum vent area of 21.69 inch^2, but is there like a maximum measurment you shouldnt pass?

there is a ratio that someone will post who is smarter than me...

 

[cjjackson85 5,000+ posts]

there is a ratio that someone will post who is smarter than me...

Anyone feel free to speak up then...

 

[Nikuk 5,000+ posts]

For a given tuning goal: You have to realize that the larger Your port mouth is, the longer the port will be, therefore taking up more volume, therefore raising tuning.

 

[Nikuk 5,000+ posts]

Fs=0.159*(((Av*(1.84*10^8))/((Vb*1728)*(Lv + 0.823*(Av^0.5))))^0.5)

 

[1990RANGER 10+ year member]

Yes.

Alright. Well then lets assume the box has a min. port area of 21.69 inch^2. Would i be bad if the port didn't go all the way across the the chamber?

 

[Nikuk 5,000+ posts]

Alright. Well then lets assume the box has a min. port area of 21.69 inch^2. Would i be bad if the port didn't go all the way across the the chamber?

MS Excel is Your friend...

Fs=0.159*(((Av*(1.84*10^8))/((Vb*1728)*(Lv + 0.823*(Av^0.5))))^0.5)

 

[1990RANGER 10+ year member]

MS Excel is Your friend...

Yea, LOL

 

[cjjackson85 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/rotflol.gif.b453361716769b8110ddefc85ff03cd2.gif

 

[1990RANGER 10+ year member]

But I still need to know, would it be bad if the port mouth didn't go all the way across the chamber but the port wall did?

 

[Nikuk 5,000+ posts]

 

[Nikuk 5,000+ posts]

But I still need to know, would it be bad if the port mouth didn't go all the way across the chamber but the port wall did?

no. i've done it a few time before.

 

[snebes 10+ year member]

It may look fugly, but if you mean what i think you mean, it will be cool. just center the port so it doesn't look fugly

edit:

I am thinking that on the inside, you wall off the unused area on the side of the port, which is equal size from the mouth to the azz, not the width of the box.

if this is not true, listen to nick

 

[1990RANGER 10+ year member]

Okay. I really dont mean to beat this topic to death since u guys already answered my question, but I just want to make sure I'm on the same page as u guys cause it seems like I may be almost done with my design //content.invisioncic.com/y282845/emoticons/veryhappy.gif.fec4fed33b4a1279cf10bdd45a039dae.gif .

In the pic below the red hatched area is the the exposed port mouth and the yellow hatched area is the intrenal port space created by the back wall and port wall.

So still, there is nothing wrong with this design?