2 12" fi btl's. enclosure help.

[lrgnation 10+ year member]

Okay this is what i know so far.

I am going to be running 2 12" fi btl's on 2 rockford t40001bd's so its about 4500watts to each sub.

I want 4.5cubes after sub displacement and port.

Sub displacement for both is about .4 cu. ft. So that puts me at 4.9

I will be tuning to about 32-33hz.

How should I make the port? For the most part the box will be somewhat normal, although I want the port inbetween the subs rectangular or to the side of the subs. heres a quick sketchup.



I could also run arrows, just need some help on port size and length, box will be about 12" high 38wide. need to know port length.

Click to read more...

 

[baseballer1100 5,000+ posts]

What are arrows?

 

[lrgnation 10+ year member]

oops aeros...

 

[baseballer1100 5,000+ posts]

I was gonna say. haha

 

[ultimate157 5,000+ posts]

I'd go with the port in the middle ... looks like a jeep wrangler. haha.

I love the port in the middle because its symmetrical //content.invisioncic.com/y282845/emoticons/uhoh.gif.c07307dd22ee7e63e22fc8e9c614d1fd.gif

 

[lrgnation 10+ year member]

i'll have some plans up a little bit later that you guys can review. It should be really close to 4.5cu ft. Its gonna have a slanted front which will actually let thebox be a little bigger. i need atleast 100 sq in of port however.

 

[lrgnation 10+ year member]

Heres a rough sketchup before the plans and without a port.

 

[lrgnation 10+ year member]

Okay its 38 wide, 12high, 27long on top, and 31 on bottom.

So i got 5.656 for the 38x12x27.

I added .41 for the extra right triangle.

(4"-.75 for wood. 3.25/2=1.625x12hx36.5L=711.5-1728=.42.)

So 5.66+.42=~6cu ft. before any displacement.

subtract the .4 sub displacement at 5.6cu ft. and 1-1.2cu ft for port. puts me right where I want it. at about 4.4-4.6cu ft.

Just need the port design now.

 

[2loud4u 10+ year member]

I got ya. just give me a bit and i will get back to you on aim.

 

[lrgnation 10+ year member]

Okay so basically I got 4.5 cubes with 79sq inches of port.

its a 7.5" wide x10.5" tall slot port and 23.75" long. port takes up 1.1 cubes so it puts me right at 4.5cu ft. at 33hz.

 

[saywhat? 5,000+ posts]

sounds good, now start building haha.

should be loud.

 

[lrgnation 10+ year member]

sounds good, now start building haha.
should be loud.

No $$ right now, working on it...

 

[gsxrjjordan 10+ year member]

Although it probably doesn't matter with SPL stuff, I've found that angling the subs is a bad idea... usually doesn't give the sound waves enough time to form before you hear them (usually, firing straight back, you get a clean reflection off the trunk and a nicely formed wave when it gets to the front seats). If you need to, slant the back rather than the front.

Also, if the port opening is on the slanted side, you won't have quite the right amout of port area (because the height will be the same, but depth different on top and bottom). Not sure how much that affects things, whenever I've done non-flat faces I've used Aeroports or rectangular vents on the back/top/flat surface.

If this doesn't matter at all for a set up this big, just call me a newb ~

 

[saywhat? 5,000+ posts]

shouldnt be a problem as sound waves in a car dont exactly have time to fully develop anyways. also, hes firing in cabin.

 

[saywhat? 5,000+ posts]

oh and, have your port on the driver side //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif