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TrlcKed_OuT
06-28-2005, 08:37 PM
ok how do i measure the port lenght on a box with a square port....do i measure from the front to the end(meaning to i hit the back of the enclosure or from the front to the end of the port wall.....or from the front to the middle of the end of the enclosure and the end of the port wall this is all assuming the port is not a L-shape...

bimma85
06-28-2005, 08:41 PM
I'm not sure if I know what you're talkin about. So you have a slotted port? You wanna know to measure from front middle or back? Port should be on same side as sub.

chinny
06-28-2005, 08:44 PM
I dont really get what your saying but if its what i think then its until the end of the port wall.

Harrison486
06-28-2005, 08:58 PM
I have no idea what you are saying...

But all ports, especially L ports, length is down the middle

TrlcKed_OuT
06-28-2005, 11:54 PM
sorry i will try to make it clear'r

yes i have a slot port with the measurement are 5'' by 15'' by ?? mox box depth is lik 25 so would it be 25 or do i stick the tape into the port and just measure the port wall....

DBfan187
06-29-2005, 06:24 PM
sorry i will try to make it clear'r

yes i have a slot port with the measurement are 5'' by 15'' by ?? mox box depth is lik 25 so would it be 25 or do i stick the tape into the port and just measure the port wall.... No, you measure strait down the center. 5/2=2.5

2.5" is where you measure throughout the port.

TrlcKed_OuT
06-29-2005, 09:31 PM
hmm im not sure how to explain ne more but ur answers arnt what im lookin for.... ok if u were to goto your box (if slot port)....tell me how u would measure ur port lenght... in best details possible....

DBfan187
06-29-2005, 09:43 PM
If your port is 5" wide, then 2.5" is the center, from there, measure your length.

TrlcKed_OuT
06-29-2005, 09:45 PM
If your port is 5" wide, then 2.5" is the center, from there, measure your length.


yes but what to what do i measure for the length...

DBfan187
06-29-2005, 09:47 PM
yes but what to what do i measure for the length...

this (http://forums.caraudio.com/vb/showthread.php?t=105291)may help you.

TrlcKed_OuT
06-29-2005, 10:19 PM
this (http://forums.caraudio.com/vb/showthread.php?t=105291)may help you.

i know how to find what the length needs to be.....ill draw a pic ....sorry i cant describe it
http://img167.echo.cx/img167/9710/untitled3qk.th.png (http://img167.echo.cx/my.php?image=untitled3qk.png)

DBfan187
06-29-2005, 10:23 PM
you lost me dude!

1st - you ask how to measure your length.
2nd - 'WE' tell you.
3rd - You tell me you kow it already...?

TrlcKed_OuT
06-29-2005, 10:27 PM
well i am gunna build a new box and i am goin with 5''x15''xlik 25 or something....but i need to know how to physically measure the length on/in the box...... i cant explain it ne other way than the pic i drew....which of the three colors would represent the port length of that box.....

DBfan187
06-29-2005, 10:28 PM
gimmie the dim's for your box please.

TrlcKed_OuT
06-29-2005, 10:31 PM
dude i dont see why its so hard to tell me what 2 points on the box i measure for the port length... i havnt finished designin the box .....but if u arnt understanding what im sayin by measuring the port length i need a real boxer designer i guess

DBfan187
06-29-2005, 10:35 PM
dude i dont see why its so hard to tell me what 2 points on the box i measure for the port length... i havnt finished designin the box .....but if u arnt understanding what im sayin by measuring the port length i need a real boxer designer i guess

#1, don't be a ****. I'm trying to help you out, but all of your posts are half-assed, as in, you're only giving me a little info to go on.

If you would gimmie your dim's, I'd have something to go on. But you've neglected to tell 'us' your desired tuning, vB, ect.

What the hell do you expect?

TrlcKed_OuT
06-29-2005, 10:36 PM
ok maybe this would be simpiler...if i was measuring a ported box to find its dimentions and tuning freg and port are ..i would measure the HxWxL of the box and the port...well if i measure the port width to be 15'' and the port height to be 5'' how would i measure the length of it??

TrlcKed_OuT
06-29-2005, 10:40 PM
#1, don't be a ****. I'm trying to help you out, but all of your posts are half-assed, as in, you're only giving me a little info to go on.

If you would gimmie your dim's, I'd have something to go on. But you've neglected to tell 'us' your desired tuning, vB, ect.

What the hell do you expect?



well im not askin help on what length i need to have a certain freq.. if u werent tryin to figure something i already know and read my posts it would help.... i know that givin my box...which is 4.5cuft or whatever that with a port of 5''x15'' that to get a tuning of 35 i need a 25'' or so length those arent exact but i know how to get the tuing im just simplily asking givin a made box sittin in front of me how would i measure its port length.....what 2 points would i meaure from...refer to my drawing would i measure the red the blue or the green

DBfan187
06-29-2005, 10:43 PM
ok maybe this would be simpiler...if i was measuring a ported box to find its dimentions and tuning freg and port are ..i would measure the HxWxL of the box and the port...well if i measure the port width to be 15'' and the port height to be 5'' how would i measure the length of it??OK, now that's better. You said you want it 25" long or something...?

Take that 2.5", and measure it 25" down the middle, stay 2.5" away for all walls.

Help any? More?


If you would tell me your vB, and tuning your after, I could go into more depth.

TrlcKed_OuT
06-29-2005, 10:47 PM
well i havnt planned it all out yet but i need to know that but its going to be like....57''xeither 15''or 20'' by 12'' it will have around 75-80 in2 of port with tuning around 35...but on the back side of the box its got a 7''x6''x57'' indent in it to fit into my truck.....but i wasnt sure how to make the port length when i actually build it...(first time builder here)

TrlcKed_OuT
06-29-2005, 10:50 PM
is there a certain amount of room needed behind the end of the port wall and the end of the box.....say the port wall is 30 and the depth of the box is lik 40 and i need a 35'' long port length would 10'' be fine?? or did i lose u again lol

DBfan187
06-29-2005, 10:52 PM
Add your port and sub displacement, to your NET volume.

Go here (http://www.carstereo.com/help/Articles.cfm?id=45)for your box dim's.

Like I said earlier, to measure the length, go straight down the center, ex. 4.5^3, 35Hz w/ 75"sq. of port, your length would be 27".

DBfan187
06-29-2005, 10:56 PM
is there a certain amount of room needed behind the end of the port wall and the end of the box.....say the port wall is 30 and the depth of the box is lik 40 and i need a 35'' long port length would 10'' be fine?? or did i lose u again lolport needs to be it's WIDTH away for the wall.

Say your port is 5" wide, make it 5"(2.5" will be the center point) away from the wall. Your 10" away, so you should be fine.

TrlcKed_OuT
06-29-2005, 10:58 PM
ok thanks alot sorry bout all the troubles i didnt know how to explain it..one more question...does the port wall have to be equal to the port length or can it be less??

DBfan187
06-29-2005, 11:01 PM
Port Displacement

if it uses of the sides of the box for one side of its port wall, then:

(port height) x (port length-wood thickness) x (port width + wood thickness) / 1728

if the ports in the middle of the box, and has its own walls, then:

(port height) x (port length - wood thickness) x [port width + 2(wood thickness)] / 1728



Port needs to be it's WIDTH from the walls, not length lol - WIDE *** PORT!