I have been playing with the crossover in the A15. Varying the first series resistor helped with the too hot HP but dulled the treble too much. Faced with the prospect of learning complex theory and then applying it I decided to try something easier first :-) I simulated the crossover using an 8 Ohm resistor as a load and varied the value of the various components and looked at what they did to the transfer function. I tweaked away with standard values until I had a curve that looked like the inverse of what I was hearing. It will be at least spring before I can measure what I build but I did find a plot of the raw horn / driver frequency response.

So now for the questions?. Is looking at the voltage transfer function of the crossover a valid way to predict changes to the system FR? I realize that an 8 ohm resistor is not a very good model of the driver/ horn combo but is it close enough for this type of work? Lastly, assuming I am on the right track will the differences in phase angle shown in the attached plot have audible consequences or are they close enough to the stock to be unnoticeable. FWIW specified stock XO frequency is 630 Hz

The attachments?. First is the phase and voltage transfer of the various models. Stock with SW1 open (closed is high frequency emphasis position) Modified XO with switch in both positions. (I am using the switch in the modified version to switch in a bypass capacitor for the first series resistor)
http://i142.photobucket.com/albums/r...ps1fd619cc.jpg

And? the Publised FR and Z of the Horn/ Driver Combo
http://i142.photobucket.com/albums/r...psb42e348e.png

Thanks in advance
M