Stupid question - multiple ports

[samson 10+ year member]

Running some calculations for a box that says the minimum diameter for the port should be 4". When I plug that into the calculation, the port should be around 16" long. The problem is, the box only has 7" to play with (funky under the rear seat thing)

Assuming pi x 4" diameter x 1 port = pi x 1" diameter x 4 ports, shouldn't they both pass the same volume of air? With four 1" ports, I can use 4.15" length to tune it.

Any experiences? Will this work and avoid port noise or do you think it'll sound like ars????? Better off just using one 2.5" port??? //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

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[iamamp3pimp 5,000+ posts]

if you think about it, one 4 inch port will have more airflow than 4 one inch ports, so you'd have to use more./

 

[GrnEydDvl 10+ year member]

Area of a circle is Pi(r^2), not 2d(Pi).

One 4 inch tube has a port area of ~12.56 sq inches.

Four 1 inch tubes have a port area of ~3.14 sq inches.

 

[xluben 10+ year member]

one 4" port area

area = pi x r^2 = 3.14 x (4/2)^2 = 12.566 in^2

four 1" port area

area = 4 x pi x r^2 = 4 x 3.14 x (1/2)^2 = 3.141 in^2

beaten //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[samson 10+ year member]

And I never thought geometry would come in handy. You're right. Looked it up.

Area = pi x radius squared. So much for my memory. It would take 16????? That right?

So much for that idea.

 

[samson 10+ year member]

Oops, my math is off. Again. Thanks, guys.

 

[iamamp3pimp 5,000+ posts]

thats awesome!

lol