Question about enclosure and port

[jarod027]

Hi, I'm building a box for two 12" kicker l5's. For aesthetic reasons, we are wondering if a single 4" diameter port can be put, and if it is possible to have that in the back of the box rather than the front like you always see.

[white4d96]

You need much more port than that.

I'm not too familiar with L5's but I'm sure someone else can give you box ideas.

As for port out the back...I guess you could do it. Not sure how you mean to do it but shouldn't be an issue.

Actually what you could do if you had like a fold-down armrest in your backseat or something is make a slot port that goes through that hole.

[jarod027]

How big of a port is needed?

[OrionStang]

How big of a port is needed?

How big is the box? How do you want it tuned?

[fecupe2001]

For a 15" i would at least 3 c/f and 1 6" port, yes the port size depends on the box size...

[jarod027]

it's 2 12" subs and the box will be around 4 c/f total. Looking to tune it somewhere around 28-34, whatever is best

[fecupe2001]

For 2 12´s and 4 c/f i would no less than 3 4" , even that i think it could have some port noise depending on the power you have.

[jarod027]

This is starting to confuse me, because I thought that it was about square inches of the port for how much cubic feet I have. And based on that I need Roughly 64 square inches for 30hz in a 4c/f box. So, by having a 4" tube that is 4.5" long, I'm at about 56 square inches, which gives me 33.8 hz

and i'm at 1200 watts power rms btw

Edited May 6, 2010 by jarod027

[fecupe2001]

That rule is mostly for slot ports, aeroport are more efficient, a round port needs about 9-13 SQ of port per cubic feet, said that, that´s why i would use minimun 3 4" ports, besides that, where do you get 56 SQ of port with a single 4" tube?????

pi x ®2

3.1416 x (2)2

3.1416 x 4 = 12.57 square inches!!

3 4" ports would be 37 square inches

Simple basic maths...

[bkolfo4]

yes the port size depends on the box size...

Actually my friend, it does not. . .but it is a nice approximation for those that cannot figure out how much port area they really need. . .