Surge protector

@immatthewj I believe you are defeating the protection that breakers provide by tripping them. Best to unplug your mains cables from the outlets. 

@vinylshadow ​​​ there is a comment up above by @jea48 and he actually addressed my question of whether a massive voltage spike could jump across an 'open' breaker, and once again, I was wrong, as @jea48  states that, 'Yes, it can, so best to unplug.'  

However, I am not sure what you mean by 

defeating the protection that breakers provide by tripping them

If I am not mistaken, the protection that a breaker provides to a circuit is that when the circuit is overloaded with too many amps the breaker reacts to the heat generated by that overload of amperage and then it trips and opens that circuit and then everything powered by that circuit is without power.  So how does me manually tripping that breaker possibly defeat the protection the breaker offers?  

I’ve ordered the Furman PST-8 unit to protect my new subwoofers once they are installed.

+1 on that, @rvpiano  , I am going to be right behind you.  Are you going to use the cord that comes with the PST-8, as I think it is an 18 gauge cord, or are you going to put a heavier cord on it?

Turning off a branch circuit breaker at an electrical panel is not the same as unplugging the equipment from the wall outlet. Distance...

Take a Square D QO single pole 20 amp breaker. In the open position the two contacts are about 3/4" apart. A several 1000 Volt lightning transient will easily jump that divide...

@jea48  , would a several 1000 Volt lightning transient  be like a direct hit?

@erik_squires  , after years and years and years of putting it off, I think I am about ready to pull the trigger on a  Furman PST-8 myself.  I note that it comes with an 18 gauge power cord--is there any down side to using a heavier aftermarket power cord with it?