Here's my problem, i have this subwoofer: http://www.rockfordfosgate.com/produ...h%20Subwoofers
For now on, my box is a 0.85cuft sealed box.
I'd like to give it a try in a ported box.
The only problem is that on this site they talk about a 1,25 cuft box with a F3=32Hz. 1,25cuft is fine with me but when i try to find the correct port lenght with winisd, it seems like the box is to small...(maybe i'm doing something wrong)
I'm planning to use a 3" pipe for the port, so could anyone help me with the lenght and the tuning frequency of the box.
thanx

 

sure...dont use a 3" round port...use a folded slot port..it will work better because you will be able to get the length you need..in WINISD just click on the round port and it will become a square/rectangle...then just punch in the port size you want to use... 3" round is aprox 7 square inches...but for a 12" sub I would reccommend more port area...say 12sq.in or maybe more depending on how much power you plan on running... and dont forget to accomodate for the amount of air volume the port takes up by adding it to the box volume...just as you would accomodate for sub displacement