Some people are sensitive to this and some are not. In fact, there was thread here on the number of CDs that were mastered with the polarity backwards. There is an easy fix, just wire both speakers out of phase which will reverse the polarity. How do you know if it is correct or not? Well I would suggest using an acoustical bass recording that you KNOW is recorded with the correct polarity. Mapleshade is a good one, because I know Pierre Sprey is very sensitive about this. In fact, he has been very helpful to me when I originally had questions regarding this matter. So listen with the speakers with the polarity done both ways. It's hard to describe the difference, but one sounds like the instrument, and the other just sounds a little funky, like the instrument is being contorted in some nature while playing (that sounds really bad--but honestly the difference can be subtle--I find the upright bass to be the most prominent but piano is also good for testing this.)
