Sub blowing Christmas lights?

electrical folks (AL?) could this be a grounding issue? Even with the sub doing something to the circuit a bad ground seems like a possible cause?

That's a logical question, Paulsax, but I can't envision how either a missing ground or a miswired outlet could cause something like this. No matter how the outlet were miswired or ungrounded it would seem that no more than the normal 120V or so line voltage would be put across the light string (unless, as Elizabeth and I suggested, the sub is adding a transient voltage spike on top of the 120V).

Regards,
-- Al

If it happens when the sub shuts off,there could be a spike from it.When I unplug the walwart for my cellphone,I get a spike.In the bedroom,it even interferes with the tv by unplugging it.I checked it with my Fluke meter,and sure enough a small spike.

Also beside the sub turning off/on doing it,there could be a loose connection in the outlet amplifying the problem if that is the cause.

Al as a rule a fuse will not add protection, blow, in an over voltage situation. I could see bulbs burning out due to over voltage....

The bulbs I assume are a filament type purely a resistive load, I = E/R. I would agree the current will spike with the voltage increase but the fuse should not see the spike, jmho......

At any rate it seems "Sprink" has left the building. Without some further input from he or she we may never find the answer.
Jim