I know how to test speaker polarity. The problem is that I purchased an amp module, and the wiring diagram was wrong, as when I played a stereo separation test, the channels were transposed. I found another diagram online for the same device and got the channels right. The system sounds fine to me, but I'm still worried that maybe the second diagram was wrong, and something is wrong with polarity. So, the question is, how do I check the polarity of the amplifier's block terminal connectors that I put the speaker wires in?