View Full Version : Port length problems

09-08-2005, 02:04 AM
So I'm trying to calculate the port length of a 3.5cuft box tuned to 32hz for my 15"SX. I searched and found a couple calculators. WinISD says the port length needs to be 66.28", but I heard it's not accurate. The Carstereo.com calculator sayed somewhere around 74", and from the same sight I used the formulas given to get 78.7". :confused: (req: don't you have a tutorial or something? I couldn't find it)

Do these numbers even sound right? It seems to me that it would be hard to fit that much port in my trunk, but this will be my first ported box so I don't really have a clue.

09-08-2005, 10:18 PM
Anybody? Please??

09-08-2005, 10:22 PM
Try this calulator, HERE, (http://accelerator-pedal.com/ported-box.asp)a couple people on here checked its results for my box, and said it was accurate. I used WinISD and it came out with completely different results... which I was told were wrong.

09-08-2005, 10:47 PM
That is a good calculator but I can't get the port width high enough. For my sub the minimum port width is 8.16" and the highest that calc goes is 6".

Does anyone have any links to the formulas (other than the ones at carstereo.com)? I'd rather just do the math myself than trust a calculator. If I find some different formulas I could compair answers that way.

09-08-2005, 11:19 PM
Why is it that you have to have an 8.16" port width?

09-08-2005, 11:58 PM
Hey bro, when using that calculator, if you want your port to be wider, just punch in a higher xmax

09-10-2005, 04:29 AM
Why is it that you have to have an 8.16" port width?

According to carstereo.com's calc it can't be less than 8.16.

Does anybody know that xmax for the 15"SX?