Ok I want to attempt my first ported box for 2 10" alpine type R's (300rms) I think I have it figured out but just need some one to clarify this first.

The dimensions are 28x11.5x14 which gives me a volume of 1.917cu'

I am tuning the box to 36hz. The port will be 10x2x17 giving me a port volume of .197cu'

The port volume plus the volume of the interior brace (forming port wall) is .243cu'

So inturn, I should end up with an overall box volume of 1.674cu' and frequency of 36hz.

The only thing that I am unsure of is if I have to take the woofer displacement into account, and I dont know if the port length is correct to give me the frequency that I want. I am unsure because I figured out the port volume using the 1.917cu' and I dont know if the ports displacement changing the internal volume has any effect on overall frequency. I think that its right, im just not positive.

Any input is GREATLY appreciated.