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View Full Version : Accuracy of online port calculators



jolly_26
12-18-2011, 04:53 PM
Decided I would run a test to see how good that port calculator off the 12volt is ( Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators (http://www.the12volt.com/caraudio/boxcalcs.asp#porsq) ) , and up next to winISD it is almost identical, got a 1% difference at the max.

Then tested this one here Car Audio - PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES (http://www.carstereo.com/help/Articles.cfm?id=31) And found differences between the other two of around 20%

This site here was much the same as well, seems pretty far off Port Length Calculator (http://www.mobileinformationlabs.com/HowTo-1Woofer-Box-CAL%20Port%20lenth%201.htm)

Had a go at the calculators on this site Speaker Enclosure Volume Calculator (http://www.bcae1.com/spboxnew2.htm)

And discovered that they are so **** difficult to use that you will probably make a mistake anyway, even if the calculations do work, but I couldn't get any decent accuracy out of it.

Had a browse through a few other sites as well, and couldn't find any others that would do slot ports, just aeros.

Verdict is, the12volt seems to do it's job, assuming that winISD is accurate. If you're looking to have a go at designing your first box, you can probably get away with hitting up the12volt for it.

Robert 2001
12-18-2011, 07:20 PM
Was just on 12v checkin a win isd checked box and was given pretty much the same answers for port size are these realy that accurate?

agarabaghi
12-18-2011, 07:34 PM
using the psp-inc.com tool for calc aero port lenghts i was getting the same results as 12v.

jolly_26
12-18-2011, 07:40 PM
I was surprised myself actually, but I guess it can be simplified and give very similar results.

wenn_du_weinst
12-18-2011, 07:45 PM
12v.com is what I always use when I get to lazy to do it by hand

kushy_dreams
12-19-2011, 03:39 AM
I was just comparing the 12v to win isd and the one on psp and the 12v and psp were identical, win isd was .5" less. Close enough for me.

TaylorFade
12-19-2011, 03:57 AM
I only ever use the 12volt one. A good way to check if one is legit is to swap the height and width of the port. Half of them will give you different tuning. Lol.

jolly_26
12-19-2011, 04:09 AM
I only ever use the 12volt one. A good way to check if one is legit is to swap the height and width of the port. Half of them will give you different tuning. Lol.

haha didn't think to test for that, definitely not one you want to be using then!