varying dvom readings after battery test

My wife made me take it to the "Pros" for install. They stated, "One of the subs is blown." I suspected improper gain setup. By 2 new subs do install my self, set the gain and voila output!

Now I want to use the old subs for another installation. Performed the battery test, cones do not push in by hand. So far so good. However, immediately after the battery test I use the DVOM to check impedance. I get readings all over the place. After 2-3 seconds they stabilize at a constant 3.7 ohms (They are JL 12's with 4 ohm impedance, I am unable to find a model number on them so I'm unsure of the rating).

Are there any other test procedures to verify if they are good?

Thanks,

Guy

A little clarification:

"My wife made me take it to the "Pros" for install. They stated, "One of the subs is blown." I suspected improper gain setup. By 2 new subs do install my self, set the gain and voila output!"

They said the sub being blown caused zero output from the enclosure. The rest of the system worked flawlessly.

Anyone have any thoughts?

Thanks,   Guy