I am a rookie trying to get into speaker building. I have a pair of Radio Shack 40-1024a woofers and would like to use XSim to design a crossover. How would I find or does anyone have FRD and ZMA files for this driver? A cursory web search has turned up nothing. I haven't risen to the point of doing my own measurements yet, but hope to. The other step in the process is to find a tweeter to use with this woofer. Thanks for any help!