I follow. You said
15000 armor protects against 30000 damage.
Where you get that it protects from 30,000 damage I am not really sure. I have never seen any indication of this. Though I have given up on armor. Not that my armor really takes many hits anyways. It's rare for enemy COM ships to get through my shielding.
He meant crystal armor mk 1, so that's 15,000 armor points. As per SirEmi, each armor point counts as two armor, so that's 30,000 armor. As per SirEmi again, lasers do -33% less damage vs. armor, so you need about 45,000 laser damage to get through 30,000 armor. Normal damage (marine, viper, nuke) would need 30,000 damage.
Is it clear now?