port help?? quick plz!!

[TLM 1]

i hope this is the right section butt....

Im still a nexb to box building and I want to make a ported box. It will house two sound splinter Rl-p 12s. I still need to find an amp so i dunno the exact wattage ill be giving them, but i want to give them like 600-800 a piece so thatd be 1200-1600 total.

I want kind of an LSQ tuning so would 34hz be alright? (thats what the site suggests) If not then just tell me what you guys would think the best LSQ tuning would be.

Then how do I figure out the dims of the slot port once i kno what hz i want??

[mrray13 30]

i hope this is the right section butt....

Im still a nexb to box building and I want to make a ported box. It will house two sound splinter Rl-p 12s. I still need to find an amp so i dunno the exact wattage ill be giving them, but i want to give them like 600-800 a piece so thatd be 1200-1600 total.

I want kind of an SQL tuning so would 34hz be alright? (thats what the site suggests) If not then just tell me what you guys would think the best SQL tuning would be.

Then how do I figure out the dims of the slot port once i kno what hz i want??

the site lists port size as 20in^2 minimum..as to length of port, maybe jmac can give u a length..it will also depend on volume of the box...but 34hz is a good place to start for sql...

my winISD is shitty...if it doesn't like the subs t/s parameters, it won't let u calculate anything... i think i'm going back to the old style...

jmac? tirefryr? anyone with bb6p???

wheeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[TLM 1]

heres the thing, i have almost exactly 4 cubes to work with, the drivers require 1.5-2.0 ft^3, the displacement of them is .18 ft^3.

So should i just use the whole 4 cubes no matter how much volume the port takes up?

[djjdnap 78]

whats that one web site hol up i'll find it

[djjdnap 78]

http://www.carstereo.com/help/Articles.cfm

[02BlackOnBlackSS 1]

Call me oldschool but I use the formula on www.jlaudio.com in the ports part of the tech section.

Never did me wrong, plus its kind of a good thing to learn the formula so you don't have to bother with askin people to figure out a port length for you.

Now about that volume situation. Is there any way you can squeeze out a little more volume? If not, just go with it. Do 40 square inches of port and tune to 35. If you go any lower, the port will take up too much volume. Once you figure out the port length, figure out how much that will displace, and if it is over .7 cubes, mess with it some more. You might have to put a little less port or a little higher tuning.

[TLM 1]

ok, because of a bunch of reasons im switching to only one Rl-p 12 rather than 2. Ill be giving it like 500-600 watts from a JL 500/1. So i still have 4 cubes to work with and the single sub requires 1.5 - 2. The displacement is .18 cubes.

2 questions:

-how big should i make the box INCLUDING the sub and port volume?

-97droptopZ, when you say a measurement like 40 square inches, is that how big the face/hole of the port should be, or what?

[02BlackOnBlackSS 1]

I would start off with 3.5 cubes before all displacement. Tune to 33ish and I would still do at least 40 square inches of port since you have the space. That is the size of the hole for the port. The length is probably gonna be around 30ish, just plug it into the formula and find out. With the JL port formula, you have to plug in lengths and you come out with the tuning frequency.

[TLM 1]

thanx alot man

but a few more questions lol

- since its in the shape of a "truck box"(deeper on the top than the bottom) ill definently need to make the port have a few turns inside the box. how deep (length from the hole of the port to the wall of the first "turn") does it need to be?

-does it matter where the end of the port inside the box faces? (assuming it would be the correct length)

thanx alot guys

Tom

[02BlackOnBlackSS 1]

I would make it go at least the width of the port before it turns. I made a box where it turned 1" into the box and it raised the tuning freq from 30 hz to around 40 hz. Pretty crazy stuff.

It shouldn't matter where the end of the port faces, as long as its got the width of the port from the wall(ex. if the port is 4" wide, make sure it ends 4" before the wall)