View Full Version : Port size

08-26-2007, 03:59 AM
3 15" shocker xtremes
13.647 cubes after displacement
Box is 49"w, 30"d and 20"h
Port will be 28.5" x 6"
I want to tune to 30hz
Carstereo.com says 12.48'
WinISD says 24.16"

Is carstereo.com taking into account the port using an outer wall for a side and adjusting?

08-26-2007, 11:22 AM
Is the 13.6 cubes after port displacement as well? I can't imagine that being so if you don't have a length for it yet...

After doing a rough sketchup, I got around 12 cubes and with a port 6" by 28.5", you need about 29.25" of port length.

08-26-2007, 12:20 PM
No, I wasn't figuring in port displacement. Did you figure that with a program and so which one? Thanks for the help.

08-26-2007, 12:32 PM
I used my head and sketchup. I used sketchup to draw out your exterior dimensions and then I drew in the 3/4" on all sides. Then I drew in your port dimensions and drew an arbitrary length. Then I used sketchup to give me the area of two sections and multiplied that by the length to get the volume of the two chambers. That was your rough net volume after port displacement. I crunched that into winisd and it said you needed 29.25" of port length. Coincidentally, I had put the length to around 28" or so. That means after adjusting a little bit should bring you close to what I have there.