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please help, i want to port my box

Discussion in 'Subwoofer Box and Custom Fabrication' started by Yates, Nov 21, 2011.

  1. Yates

    Yates New Member

    ive been reading for days and days trying to figure out port requirements for specific hz tuning and i can not seem to get it....

    i have 2 kicker cvr 12" subs, currently my box is a dual sealed enclosure, the box is divided in the middle, each inside measurements are 14" tall x 14" deep, x 14" wide each. this give net 1.51 cf airspace after speaker displacement. the minimum required airspace for ported is 1.76 cf. i would really like to remove the center divider so the subs can share the airspace, i know the minimum required airspace per sub is reduced when the subs share airspace and i believe this would be adequate but i have know idea how big or long of a port to install once the center divider is removed...i have really grown to respect the advice i have seen you guys give ppl in the past. please help..
    i would like to be at around 34 hz
     
    Yates, Nov 21, 2011
    #1
  2. Yates

    Yates New Member

    i forgot to mention they ar dvc 2ohm subs
     
    Yates, Nov 21, 2011
    #2
  3. pedro quiroga

    pedro quiroga Well-Known Member

    just have a new enclosure built, you don't have enough airspace for a port. maybe for one sub, but deff not two.
     
    pedro quiroga, Nov 21, 2011
    #3
  4. Yates

    Yates New Member

    thank you pedro, i would like to know if theres anything i can do to modify this box, it fits perfectly in the trunk space, i can remove the divider, i can also remove the back of the box and make it deeper but i dont know how deep to go, and i also have know idea how to figure proper port sizing and lenght.
    i just know that these two cvrs should do way better than they do..
     
    Yates, Nov 22, 2011
    #4
  5. Ranger SVO

    Ranger SVO Full Member

    I think pedro is right. If we remove the center divider we will have 3 cu ft to work with. If we use two 4-inch ports tuned to 35Hz the ports will need to be 14-inches long. But we need to keep in mind that the two 4-inch ports will take up airspace.

    Now lets look at something, as boxes get smaller they peak higher, regardless of how its tuned. If you decide to port it, fine. But lets get real on how its tuned. A small box tune low really sounds bad. More like awful. Lets try a tuning a little higher. If we tune to 40 Hz the ports will need to be 10-inches long. This will work in your box but just barely. But it will work. Now the natural box peak and the tuning will work well together.

    By the way, removing the divider, or just cutting a large hole in it will improve the sealed box performance.
     
    Ranger SVO, Nov 23, 2011
    #5
  6. Yates

    Yates New Member

    thank you Ranger.....i was really hoping you would respond...i will remove the center divider tomorrow and try that first, then if it still doesnt sound better i will add the 2 4" ports ( im assuming your meaning round) any specific place on the box they need to be? the speakers are centered in there respective side between the divider and the end of the box.
     
    Yates, Nov 24, 2011
    #6
  7. Ranger SVO

    Ranger SVO Full Member

    Yes Round ports

    The best place for the ports will always be on the baffle board (the board the speakers are mounted to). The second best place is the side of the box and both ports must be on the same side. Also pick a side that is close to a panel or something the sound can reflect off of. The side firing port degrades performance, but if we can reflect it off something we get alot of that sound back.

    Anyway I still recommend a slightly bigger box, but give this a try. I wanna know how it goes.
     
    Ranger SVO, Nov 24, 2011
    #7