"** Sure - put the stereo pair out of phase. "

That is NOT what I said !

Reverse the phase of ALL the speakers, then they wind in phase with each other but in the oposite phase regarding the phono cartridge.

I've done this a whole bunch of times and sometimes it does have a quite significant effect. The problem is that it's a 50/50 chance that it could get worse. In that case reverse them all back.

Concievably you could accomplish the same thing buy reversing both channels of the cartridge itself, but it is not designed for that. Some of them automatically ground the shell to one of the - terinals. Even if not it still kinda beelongs one way.

Ergo, you reverse the phase of the speakers. All of them. Unnastan now kid ?