Center channel phase question.

Here is a great way to test phase, if you have any THX movie DVD's there are Optimizer menus where you can test for phase, if it is in phase it will sound properly anchored to its position, if it is out of phase it will be hard to place where the sound is coming from, if you dont have a THX disc try and rent one, the color tracks can be fun for casual TV tuing aswell.

Mike has a good idea with switching leads but you can do this test he suggests and have better results by simply using your calibration test tone so you have a steady easy to hear signal.

I wouldnt say most Pros and Recievers do that automatically, it is gaining popularity but far from the majority.