Well, i tried and tried, but i cannot find out the new value for Lc with a 4" port. I think i`m messing it up with the unit conversions. I hope you can help me, AGAIN.

PiAlign gives me the following data:

Encl Vol: 5 cu.ft.
Encl Fr: 29Hz
Encl Q: 2.48
Port Type: Cylindrical
Lenght: 6.2"
Area: 15 sq.in.
Diameter: 4.48"

I think thats all one needs to calculate the new port lenght. I want to make the port 4" in diameter. Which lenght would the port have then?

Thats all. Sorry if i`m bothering you.

Thank you for your help!

Pilkar