speaker makes cracking sound during thunder

[Dusty Chalk]

No, I think he means actual thunder -- dude, you just need some power conditioning. The lightnight strike is causing a disruption in your otherwise...alright, it's not really clean power, it's actually pretty dirty, but at least it's consistenly dirty, whereas the lightning strike is singular. So it gets into your power supply, which means it gets into your amp, and it translates to the popping sound you're hearing. The better the power conditioning, the quieter the pop will get. The best is completely regenerated power.