slot port tunning?

[michaellane 5,000+ posts]

as much as you want, thats not going to effect tuning much, except for the fact that if they are mostly external that will give you more volume inside the box. and if you do that, you'll actually lower the tuning a little bit.

okay so how much of the 17inch long pvc pipe should be outside the box for 37hertz?

 

[01 S 10 10+ year member]

so all i need is to build my box to the specs i have listed then cut out the wholes for TWO 4inch round pvc pipes that are 17inches long? and it doesnt matter how much of the pvc is in the box or sticking out? and this is the same as slot ported at 37hertz?

yes 2 4"s, same 37hz tuning.

but like i said above, if 16 of the 17 inches are OUTSIDE the box, your volume inside will be around 2.75cf giving you just about a 35hz tuning. if both ports are mostly INSIDE the box, you'll be at 37hz, because your volume inside will now be around 2.4-2.5cf inside the box.

 

[michaellane 5,000+ posts]

not to sound rude or dumb but mamn i cant beleive it could be this easy lol. ive never tried pvc ports...

 

[01 S 10 10+ year member]

not to sound rude or dumb but mamn i cant beleive it could be this easy lol. ive never tried pvc ports...

ive used 4 4" PVC's on a build before, it was my first experience with round ports and the tuning was dead on. the car peaked dam near where we tuned the box at. this was a Buick Lesabre. something like 38hz i believe it was and sounded good too

 

[michaellane 5,000+ posts]

could you tell me this...how do i figure out cubed feet? like id like my box to be around lenght23, height 15, and width 20' but im still looking for 2.5cubes

 

[dman4486 5,000+ posts]

could you tell me this...how do i figure out cubed feet? like id like my box to be around lenght23, height 15, and width 20' but im still looking for 2.5cubes

cubic displacement is length x width x height

now to get it to cubic feet, you need to divide each measurement by 12 or the final number by 1728

 

[01 S 10 10+ year member]

could you tell me this...how do i figure out cubed feet? like id like my box to be around lenght23, height 15, and width 20' but im still looking for 2.5cubes

remember those are external dimensions too. if your using 3/4" MDF, take 1.5" away from each of those numbers, then multiply and divide it all by 1728.

im getting 3.1074218 cf. (not including the ports and sub)

 

[michaellane 5,000+ posts]

okay i think im getting it now. but if i change the length or anything doesnt that mean the PVC would now have to different lengths?

also has anyone ever used efs instead of mdf?

 

[01 S 10 10+ year member]

okay i think im getting it now. but if i change the length or anything doesnt that mean the PVC would now have to different lengths?
also has anyone ever used efs instead of mdf?

change the length of what? the box, yeah the second set of dimensions you gave us will give you a slightly bigger box. so the PVC will need to be a different length to stay tuned at 37hz

with the both round ports inside the box, they need to be 16" long. if you have them external, they only need to be 14.5" each. im including sub displacement in these measurements too (.25cf typically).

 

[michaellane 5,000+ posts]

okay thank all you guys...when i decide on the exact specs i will let you guys know so you can tell me if everything sounds okay.

 

[jaymann107 10+ year member]

I'm not sure how acurate this site is or if I should even post it here, but it might help you out. It has both slot and round port calculator as well as a volume calculator for just about every box.

http://www.the12volt.com/caraudio/boxcalcs.asp

 

[michaellane 5,000+ posts]

kool kool im going to check that page out.