My subs manual says
3 x 12.5” (7.6x31.8cm) port, 20.5” (52.1cm) long
Power Handling = 300W RMS
5 ft^3 + port displacement
for a 12" vented enclosure. The enclosure I'm designing is pictured below for two subs. Do I double the port dimensions? This seems uber small for how big the box is. I used another web sites calculator (PORT Size Calculations and Formulas for WOOFER and Subwoofer BOXES) and it says when I enter my port dimensions "you should use a width:height ratio of less than 1:8" (with dimensions 3"x33.5", volume of 5ft^3, 35hz tuning freq).
If I change the dimensions to 3"x24" it will do the calculating and say the length should be 12.68".
So at this point I'd like to know what is my designs current tuning freq (I'm aiming for 35hz) and if I need to downsize my current port.
My current designs net volume (with port and sub displacement subtracted out) is 4.89 ft^3. The external dimensions are 35"x14"x27".
http://www.kicker.com/sites/default/...2007CompVR.pdf < sub manual (12" 2 ohm DVC)