The surge came in through the cable box coax cable. I use both an isolation transformer and a series mode surge protector, brick wall or surge-X, and an Exactpower unit to control for brownouts. I am in a rental but in my last house I used gas arrestors on the cable lines. The series mode surge devices are UL rated for 6000V, 1000 repetitions, with no degradation.

With all of that protection, lightning can fry component level items on circuit boards through the energy in its plasma field if the strike hits your house. I had that a few years back with my powered Genelec sub.

Purists may say directly into wall but my system was sounding pretty sweet prior to this disaster.