I have two questions:

First: can i mix two slopes for the midrange driver? for example, 18dB (3rd order) highpass and 6dB (1st order) lowpass.

Second: PiAlign gives me a port that is 4.48" in diameter, lenght 6.2" and area 15. If make the port diameter 4", which would be the length?

Thank you very much!

Second, about box tuning. Use Helmholtz formula (shown below) to find the resonant frequency.

You can find also this formula in the "Pi Alignment Theory" paper.

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