test crossovers or capacitors with frequency sweep

Hi everyone - I know that with an inexpensive calibrated mic (eg umik) and cheap/free software that generates a frequency sweep you can produce a frequency versus loudness curve for your speakers. If you have this curve from the factory (it came with my speakers, Celestion 700) can you examine the match between your curve and the factory one to see if of some of the crossovers have changed? Wondering if I should recap as I just bought these used, and this seems like a way you could see if there is enough of a change to matter. Thanks for your help.