Try taking the recording to a stereo store and listen to thier system to see if the voice is centered to begin with.
As said earlier in this thread not all recordings have the voice centered. At home try this, measure the distance for you to the speakers and make that the same distance between the two speakers. Then try moving the speaker that the voice seems to be favoring further away till you get it to be center. Also reverse the output to see if there is a problem with your amp or speaker, is one speaker loader than the other. This will cause the image to be more to the opposite side. Make sure all the drivers in your speaker are working the same.
As said earlier in this thread not all recordings have the voice centered. At home try this, measure the distance for you to the speakers and make that the same distance between the two speakers. Then try moving the speaker that the voice seems to be favoring further away till you get it to be center. Also reverse the output to see if there is a problem with your amp or speaker, is one speaker loader than the other. This will cause the image to be more to the opposite side. Make sure all the drivers in your speaker are working the same.