When creating a box...
 

Im looking at making a box for a jl12w3v3-4 and my question is.

The website states - 1.75cu ft, tune to 30hz, and F3 = 36hz

i would like to know what f3 is first of all. Next

When building this box, is there a magic ratio i might be looking at for height width depth? or is anything that has the right "1.75 cu ft" going to be the same?

and when it says tune to 30, and 36 f3... am i building the box for 30hz, or 36hz? how does this all play into effect?

here is one its tuned to 32hz but you will not notice the difference.
as for F3
the F3 or the system roll off frequency is calculated using the thiele-small formulas and indicates the freq at which the low freq system begins to come ineffective the f3 piont is the freq at which system responce is down by 3 db and there fore is considered out of range
http://img62.imageshack.us/img62/514...z26sqin2rg.png

ok, well, that makes sense.

Now, i have space issues. so again, when designing my box, can i mess with dimesions, as long as the voume of the box stays the same? or will this screw with the sound?

the reason i ask, is the space i have to work with is 15wide max, 18 deep max, and i can make the rest up in height.

im looking for a ported box, sub facing up, port facing up, tuned a frequency thats going to allow the sub to be tight and controlled most commonly, but when i want to play with it, have it hit some lows. Nothing too crazy though.

i was told to tune it to 50hz, but, i think thats way too high.

i listen mostly to metal, but like to throw some different bassy stuff in there every so often. and right now , it sounds pretty good, i just want to build a new box, so i have more room behind the seat.

the one i currently have is (what i was told) 35hz with 1.75cu ft

not sure on the port dimesions inside, but, 16" tall 17.5 wide, top depth 14" bottom depth 18" ... with an L port, 1.5 wide.

yes you can mess with the size go to the12volt.com and look for the box building calculators

Yes you can....no it wont.....and don't have 2 of the dimensions the same size i.e. 24" X 12" X 12"

Also keep in mind if you change the size of the port area you will need to change the length of the port as well.....:smokin:

HTH

thanks to both of you, so now finally. all i really need to know... is what should i use for volume and tuning?

Given i want it to pound now and then, but still want to listen to metal, commonly with 16 fill double kicks, etc. (which like i said, its handling fine right now) but. since im building a new one, is there any fine tuning i should do?

i was told 1.45 cu ft at 50hz .... jl reccomends 1.75cu ft at 30hz, (which im assuming is more for "hip hop" and such?) so. im a complete noob here. any insight to what i should be looking at? and what it will do changing these?

also, top depth and bottom depth?.. must they be different as well? or can they be the same? or does that only apply for the main 3 dimesions, height depth width?

The smaller box is tuned way too high for a daily driver.......every JL speaker I've heard in a "spec" box has sounded great, I would stick with that unless you don't mind making a few boxes to see if one works better in your vehicle with your music.....:dunno:

My opinion is ,you would be more satisfied with a sealed enclosure