A few months ago I bought some old (quite good) speakers. My first step, of course, was to use a calibrated mic to measure them. One measured way better than the other. Took them apart and realized at some point someone had connected wires incorrectly on one of the tweeters causing it to be out of phase. Do you know what this means?

I REVERSED THE POLARITY AND FIXED MY AUDIO PROBLEM. That day I became a Starfleet Engineer.

That, or inaprovaline

I thought it was an inverse tachyon beam from the main deflector array

When switching from flux core wire to regular wire with shielding gas on my welder it calls to reverse the polarity of the electricity to the welding gun. You have to open it up and swap two wires around. It always cracks me up inside when I’m telling people I had to reverse the polarity of the welder to get a better weld.