View Full Version : Port Plug ???

05-04-2004, 05:11 PM
Ok, I am getting my system hopfuly this summer and am cerious about using a port plug rather than using 2 seperate boxes. What is it and what exactly does it do. I know it allows you to changed the tuning of the box but how? And how hard are they to build. I would much rather build 1 box and use a plug then have to deal with 2 boxes.

Oh my system is in my sig to give you an idea what my 2 boxes I want tuned to are...

Your input is appreceated...


05-04-2004, 06:45 PM
They are not that hard to build, but once you choose your base port (higher SPL frequency) it limits your choice of SQ frequency.

For example, your SPL port is 3 inches wide, 13 inches tall, and 10 inches deep and it is tuned to 45 hz. If you want to make an SQ plug that is the exact same length (.75 MDF), you will have a 1.5 inch wide, 11.5 inch tall, and 10 inch deep port. Let's say this is at 30 hz. This is the easiest way to do this, but it limits the frequency that you can tune. If you want to make it shorter than 10 inches, the calculation will be a little more difficult. If you want to make it longer, then just calculate as normal. Just make sure that there is enough room on the opposite end of the box so the port width is the same as the space between the port and the back of the box.

This may be a little confusing, but it is right. You can experiment with this on WinISD.

05-06-2004, 11:03 AM
You can always put a little nub on the side of the port that keeps the volume of the port the same but you'll have different dimensions then. My friend did 40, 35, and 30 for his HC15. I'll get some pictures up eventually if you would like.

05-06-2004, 11:49 AM
Also, the port can extend outside the box of you need it loger than will fit for the lower tuning.

05-06-2004, 04:52 PM
Yes pics would be good!! So are the hard to make or not?? Either way to save me some money (yes i'm VERY cheap) I will probably only get 1 box and then just make a plug. Thanks for the help guys...


05-06-2004, 09:39 PM
The one thing to remember when making a port plug is to make the initial port the higher of the frequencies that you want it tuned to. I believe, and somebody correct me if I'm incorrect, that the easiest way to do this is just extend the port by having it outside the box. If this is the case, then adding port length (decreasing tuning frequency) is not hard to do and should give you great results but just a little extra port which you may or may not want.

05-12-2004, 04:54 PM
Lombardo, i was just cerious if you were still going to put up some pics. Just would like to actully see it so I can figure out how exactly what i need to do in building one...

Helotaxi, how would you take it on and off?? Wouldn't it have to be sealed or am I just over complicating things???