That's why you need to buy and read the book.
Until you understand the concepts of sampling, resolution, windowing (apodization), near field, phase unwrapping, truncation, time vs. frequency, and gating, what you're going to end up with is a bunch of messy curves that tell you more about your measurement errors than about the loudspeakers.
Here's link that will give you a flavor of a few of the issues, but really, if you want to do something useful, you need to go into much more depth and practice.
http://www.bksv.com/doc/bo0102.pdf