From time to time the proposition is put forward such that the speaker should move forward with a positive input pulse to the amp. The test, unless I have missed something, (and THAT sure can happen) has been to make a speaker cable polarity reverser, of some sort, and try both ways, pick the preferred configuration and enjoy the max in sonic response. It dawned on me that the old pickup polarity test, using a meter and bringing a metal rod (screwdriver, here) in contact with a pole piece generates a viewable/measurable pulse. Soooo....whack your pups with some metal and watch or feel the speakers hop. This seems to work. You may want to verify that your pup is wired to respond positively to the contact. Stiff cones take a good bit of power to pulse visibly. It's quick. Once you master the method, checking the whole signal chain, pedals and all, for signal inversion, should be possible. I haven't done that, yet. Fitting reversed speaker cables to cabs, once you have determined your amp's polarity, may become necessary. All amps are not the same, so you may need to fit or provide 2 separate cables and use according to the amp's needs as you swap cabs.