View Full Version : Can someone double check me

05-14-2004, 12:54 AM
Ok, so this is my first ported box design and and i wanted to kno if im correct andif someone could double check me on my thinking and calculations, thanks alot if you'll help. Look at my pick and the lingths should include the calc of 3/4 in mdf. and i figure with thoughs dementions i should have 1.6cf per side plus the .128cf displacement of the subs and the .131 displace ment for the port(including the mdf). the port is 10 feet back. if im correct that set up should b around 41-42 hertz and if im correct i could put 1/2 inch mdf in the port making it a 3x3 port instead of 4x4 droping it to 32 hz, correct me if im wrong. also hears my calculations.

0.159*(((16*(1.84*10^8))/(3212.352*(10+0.823*(16^(1/2)))))^(1/2)) for the 42 hz rating

(0.159*(((9*(1.84*10^8))/(3212.352*(10+0.823*(9^(1/2)))))^(1/2))) for the 32 hz rating

this box is for a type-r 12 inch sub. thnx a lot ask any questions if you don't get what i siad, thnx

05-14-2004, 02:53 AM
Looks like a righty using his lefty! Should use Textboxes.

But i'm not sure if u want to have 2 different tuned subs playing at the same time.

I'm sure it can be done, but can't really imagine how the output would sound.

Another thing, i'm seeing all these figures in your equation, but not seeing them in your drawing or explanation.

Where di you find this formula?

05-14-2004, 03:37 AM
I've found that it is usually easier to build vented enclosures with a common chamber and a single port. You won't have to worry about differences in tuning, and you only have to make one port. Also, you might want to download WinISD or some other program for calculating tuning. It makes things a lot easier.