Knowing what frequency your crossover is set to?

I am playing around with the integrated subs in my Strata Minis and I was just wondering if there is any way knowing what frequency I have my crossover set to? I mean, the exact HZ. Most plate amps have a low number/high number listed but thats it... Is there a sure way of knowing the in between?
First, is there any good reason to know, other than curiosity?

Second, get a microphone or sound level meter and you can measure it.