I had a non-hit from a nearby lightning strike once that took out both the amplifier and tweeters of the speakers, even those the entire audio system was unplugged (if I can, I do so during storms just in case since I've witness several incidents in my life of lightning coming in). I guessed the cause of this was due to having "monster cable". But it's not the cable's fault. I originally had the system downstairs and to avoid a shaky front room floor from disturbing the turntable, I put the system in the back room and ran the speaker cables to the front room. I used 75 feet of "monster cable" (was about 6 gauge stranded) to minimize loss and resultant distortion (since speaker impedance varies by frequency, resistive loss in the wire will affect some frequencies more than others). Later when I moved the entire setup to a special listening room upstairs, I didn't want to cut the speaker cable because it cost so much, so I just coiled up the excess in an otherwise empty closet it ran by. I figure that was the bad move as it probably enhanced the effect of the lightning's EM field on the induced voltage. The amplifier power transistors were fried. And the tweaker coils were melted. The crossover, bass speaker, and other electronics survived. It cost about $150 to fix that mistake. It cost another $12 to get some shorter 12 gauge speaker wire to put in place of the "monster cable". Lesson learned.
