View Full Version : port help

03-05-2008, 07:12 PM
I have 6.75cf net for 2 HDc15's and to have the right port opening I need to add 10sq in. now I have some 3in inner diam. pvc to get close to 10sq in would I need to add 2 of these or how many sq in. is in a 3" diam. opening. Thanks

03-05-2008, 07:28 PM
you need to add another 10in^2 in addition to the one you have now?

03-06-2008, 06:41 AM
yes it's an old box that I had my BTL18 in

03-06-2008, 06:46 AM
modified an old CRX style box and want to see what numbers I get before I decide to wall it off currently have 85in^2 but need closer to 95