I have a silverface Fender with a JBL D130F. The speaker cable is the standard plug into a jack on the back of the chassis with a black and white wire going to the speaker. For now the black is hooked to the black terminal on the JBL and the white is hooked to the red terminal. Somewhere I had read that the polarity on a JBL speaker was reversed from most speakers - that the black wire on the amp should go to the red terminal on the speaker. If I do the 9V battery test and touch the + battery terminal to the tip and the - terminal to the body of the plug the speaker moves backward toward the magnet. Is this correct or do I need to reverse the terminals?