Hey guys,

I'm just in the process of designing a new box for my 12" Brahma MkII.
I currently have a 2.5CF box tuned to 30hz.

I want to make one that is 2CF tuned to 35hz. (preferrably dual port)

I went on a couple sites to calculate the port length. With a net volume of 2CF, 3" port diameter, and tuning frequency of 35hz, its coming to 13.36" for each of the two ports. OR 5.58" for single port.

Does that seem right?

Furthermore, are there any drawbacks to having a port diameter of 3"?

Any other suggestions on the dimensions to use or anything? Any help is appreciated.

Thanks,
Dev

I used my Box Program and with 1 12" in a 2.5 Cu. Ft. box Net volume after subwoofer and port size taken off or 2.712 Gross Vol., 2 3" ports 9.3" long will tune you to 35hz., or 3" port 3.9" long for single port.

I think 3" ports will be fine for your subwoofer and box combo.

If you need any more combo`s or tuning tried just message me.