port calculating problems

[bigtbuck]

hey guys, heres the deal. im building a box for my 12 inch type r. its going to be 1.4275 ft^3 after displacement and i want it tuned to ~ 30 hz. when im typing in the information on a port calculator it tells me my slot port needs to be 47 inches long. i typed in 12.5 inches for the port height with a 2 inch width. What am i doing wrong here, that doesnt sound right?

my dimensions (external) are 14hx16wx18d.

If you can help me out here, it'd be appreciated. If any of you have a ported box you've made i'd appreciate the dimensions and how long your port is. i need them as soon as possible

[bigtbuck]

well im very new with all of this stuff. i want to build a box with a slot port, tuned to around 30 hz. do you got any suggestions?

[bigtbuck]

alright thanks jmac. i read about your car getting broken into, that *****. just whenever you get the time man

[bigtbuck]

just moving the article back up.

jmac your help would really be appreciated whenever you get the time

[bigtbuck]

alright thanks a lot jmac. i was typing on the port calculator but i didnt think i was doing it right, i didnt know it was normal for the port to be that long, but then again i dont know anything about ported boxes. sorry for bugging you, i know i had 2 or three different threads that were all pretty much about the same thing and you posted on all of them. i just assumed i'd messed up on the port calculator. but thanks a lot you've showed me how this needs to be done so hopefully from now on i'll be able to design my own boxes.

my next project is to replace my sealed box for my edk. only problem is it goes underneath the seat in a 99 extended cab, so it may be awful hard to make room for it. i'm wanting to get another one (i've got one 10" k right now), but im pretty sure it'll be impossible to port two k's with as little space as i have right now.

but thanks again for all your help.

[bigtbuck]

i guess i do have one last question:

does it matter where the sub is placed? like does it need to be over close to one side, or in the center, or what?

thanks

[jlaudiow6]

Where do you get the slot port calculator? Cause i'm makeing a fiber glass box for my car but the speaker is too heavy and the enclosure will roll if i brake really hard.

I need to make a bigger enclosure with Slot ports to make the enclosure ;more stable in my car for driving.