Difference between polarity and phase w/sub

The polarity switch inverts the polarity of the woofer 180 degrees, while a phase control might give you continuously variable phase change (my Paradigm allows change from 0 to 180 degrees). To do this simply, with both the satellites and sub playing a recording with a consistant low bass instrument, turn the phase control until you get the most bass. Then you can play with the polarity invert feature to see which position sounds more natural to you. You could also do this with a test disc and a meter as suggested above, but it's probably not necessary. Regardless of the amount of control you have, there is no substitute for proper placement of the woofer in the room... Move it around and leave it where it sounds the best. Sometimes moving the woofer a matter of inches makes for profound audible improvements. I usually position the satellites for best bass first and subsequently position the sub.