Polarity/phase is really important! I enjoy having a phase switch on both my PS Audio DAC and my PS Audio phono preamp. They get used!

For My system, I just reversed the output leads on the torrii amp, positive speaker output from the torrii to the negative input on the speakers and negative speaker output on the torrii to the positive input on the speakers, for both channels. changing the phase is probably a better description of what I did by switching the inputs and outputs. how the speakers changed polarity or why they sound better with a reverse phase, not too sure what happened with the system.

the speakers I am running are not full range transmission line type speakers, they have a two way crossover, 6" woofer/mid and a tweeter for each speaker with some sort of, as polk puts it,
"Capacitive Coupling Technology that enhances the bass performance" .