port tube lengths?

[ForOffRoadDriving]

so ive got this Q logic box (model QLT-108BP.2) and it got a little wet some where along its lifetime. it had thick cardboard tubes attached to the platic inserts, but because of the moisture they crumbled when i removed them and at the time i didnt think about measuring them (length) before discarding them. the ports are 3" in diameter and the box is .35 cu ft in the sealed portion and .26 cu ft in the vented portion. does any one know how to figure out how long these should be? (in the picture there are some serial boxes taped around the ports, but my little brother put them in so i dont know if they are the right length)

 

[baxtej44]

check the manufacturer's specs, that's all i can really guess.... it purely depends on your driver, i believe.

 

[4x4fun]

it purely depends on your driver, i believe.

yes

 

[4x4fun]

orrrrrrr

Lv= ((2.35625X10^4 Dv^2 Np)/VbFB^2)- KDv

diameter of vent (Dv)
number of ports (Np)
volume of box (Vb)
frequency of box (fb)
end correction factor (k)

good luck with that lol

 

[ForOffRoadDriving]

i found some vague specs on the sub http://images.google.com/imgres?img...images?q=kfc+w2002&um=1&hl=en&sa=N&tbs=isch:1 and the only web site i found that even acknowledges that that model exists gives no pictures and only lists dimensions of the box http://www.totalautoprotection.com/speakerenclosures.htm

 

[ForOffRoadDriving]

i found this site with the built in calculators http://www.the12volt.com/caraudio/boxcalcs.asp#por, but im not sure how to find the tuning frequency, is this going to be the frequency that i want the sub to amplify the most or is it a preset value that is calculated by the dimensions of the box? so far the values i have are 3" port diameter, x2 ports, .26 cu ft air space, i dont know my tuning frequency