Rebuilding my tops, neew help with hornr

Hi guys!

I´m in the planing phase of a rebuild of one pair of my tops.
i´ve been drawing and thinking of a new design and i have been fitting a HD-15-ish kick part in to the box.

Now i want to do a hornresp sim to se if the design is worth a go.

But it seems to me that i´m to stupid to understand hornresp :S
How should i set up hornresp to sim the "hd-15"
and witch measurements should i do to get the correct sim?

The driver i want to use is a Fane Sovereign PRO 15-600LF.

I´ll attach a pic of my design, the with of the horn is 425mm


I hope anyone can help me so i can move forward with this rebuild