Quote Originally Posted by RMC View Post
Since port length is increased a little it will tune the box a little lower. In order to keep the same box tuning frequency then you have to increase port area a little, which tunes higher, in order to go back to where it should be.
Ah yes, that is what I'm after. I never could get my head around calculating the port area for different size & shape ports.
What size would the slot need to be if I increase the baffle to 1&1/2" ? or can you point me to somewhere I can calculate this?

Some have suggested I use a 6" circular port, but again, I don't know how to calculate the length.

Cheers.