That "crackle" is your indicator of atomizer health....worry if it doesn't. When the hit, taste and vapor start going south, pull the tank, unscrew the atty, and blow through the battery end of the atty holding a paper towel over the tank end. Lots of
juice will come out. When that produces no more
juice, twist up the towel and swab out the atty end....plug/screw it all back together and enjoy.
I do that procedure every night at bedtime and don't reassemble the unit until I get up the next morning. Every other or third day, after that procedure I soak the atty in grain alcohol overnight. Blow it out from the battery end next morning and wipe it dry....reassemble and happily vape. Four more days and it will be two months on the same hardware....no failures and everything still works as new.
You may experience some occasional tank leakage....watch this video for the cure that worked for me: