View Full Version : port bend question

10-29-2004, 08:13 PM
i am building a box for my reg. cab silverado. I am putting a 13kv2 ported to 29 hz in a 1.5 cu.ft box. Here are the box dimensions (all external)

top depth....................5 3/4
bottom depth..............8 1/4

port area- 1.75 x 12.5

the only way i can fit a port with enough port area is to have one width of the port 12.5 in. in other words i'll only use a single sheet of mdf for one side of the port (the other three would be the actual box so that the port will take ip the leaslt amount of airspace possible)

I want the port to come out in the middle of the top of the box and bend to the left . i have noticed when a bend is put in a port it "stacked"...but with mine the bend would be different than normal... the top sheet of mdf on the top of the box will have a hole cut in it for the port end and the port would IMEDIATELY bend to the left leaving only 3/4 of port length (the thickness of the top sheet)on the left side of the hole. on the right side of the port end it would go down all the way to the bottom of the box. to me it would make it seem like just a hole in the box on the left side and not a "port" but when u look at it on a sheet of paper it looks like it could work... Would this work right?????

Basically its a port bend the opposite way it is normally bent...

any1 have any insight on this

i can draw a picture of the design if that would help cuz i know what i just said is hard to follow.

10-29-2004, 10:18 PM
here ya go


the drawing is without the front sheet and top sheet (which the latter is drawn above) just to make it simpler. The top piece with the port end goes down directly on top of the box forming the port end and the fourth wall of the port. The bottom of the box forms the bottom wall of the port and the back wall forms the back wall of the port. The part I'm worried about is that with the top pieve forming the fourth wall and the port end there is only 3/4'' on the left side of the port. Do you see any problems with this? It seems like it would be just a hole instead of a port.

10-29-2004, 10:18 PM
sorry for crappy pic/drawing

10-30-2004, 08:32 PM

10-31-2004, 01:56 PM
so u dont see a problem with the left side only being 3/4'' and the right side being 13.25''?

it just looks like it would be a hole instead of a port.

10-31-2004, 02:03 PM
also is 36 in. long for the port length with a port area of 1.75 x 12.5 correct for a 1.5 cu.ft. box tuned to 29hz with the above drawing. I'm not sure with how long it should be because i dont know if that is a slot port or not and whether to put the height as 1.75 or 12.5 or whether to put the width as 1.75 or 12.5 in the port calculator on carstereo.com. when i switch the height and width number there is like a 6 in. difference in port length. which is right?

10-31-2004, 08:40 PM
good luck with it sometimes it is the guess and experimental ports that work the best let me know how it works

10-31-2004, 10:32 PM
You mean there would only be 0.75" between the end of the port and the wall ? Because it would have to stay 1.75" ...
no. more than likely it will crook back. i just didnt draw that because that was irrelevant to what i was asking. sorry for the confusion.

what i'm askin is , is with the left side of the port opening (the top piece drawn above) will only be 3/4 in. deep and the right side of the port opening would extend down 13.25 in. making the port look as if it was just a hole. does that look like a problem?

also i need some help on the port length. it's either 36.75 or 42 but i dont know because on carstereo.com if u put 1.75'' on the height of the port it is 36.75'' but if u put 12.5'' on the height of the port it gives me a length of 42''...which one????? help...

11-01-2004, 08:06 AM
As long as it stays 12.5" x 1.75" all the way through, it's fine ... So, if you're saying what I think you're saying, it's fine ...

It would be 36.75" by that calculator ... Remember to measure down the center ...
thanks for your help :thumbsup:

when i'm through there will definetly be pics....