Center image on left side and don't know why

I too have been plagued with this problem from time to time. It has almost always been solved by speaker placement, toe in and/or distance from the listening position. It is amazing how seemingly insignificant changes in these two factors can cause dramatic shifts in the image. If your system is set up properly and everything is working properly, you should be able to look at the spot where the vocals are coming from, and that spot should be centered. I find it hard to believe that you can trick yourself into thinking it is coming from some place it is not, especially when you are concentrating on it.

Here is a simple way to tell. When I think my image is centered, I turn my head to look left of center and the image comes from the right of where I am looking. Then when I turn my head to look right of center, the image comes from the left of where I am looking. In other words, even when I turn my head, it is still coming from the center. If the image moves left when I look left or to the right when I look right, then the image is indeed off center in that direction.

To see if it is something wrong with the system, move the left speaker to the right and vice versa but leave everything hooked up the way it is. Hopefully your speaker cables are long enough. That way everything that was feeding the right side is now on the left, and vice versa. If the image is still off center in the same direction, then you have a problem with one of the following:

a. toe in
b. distance from the speaker to the sweet spot
c. some sort of interaction with a room irregularity
d. a hearing problem

Have you checked to see what happens in "mono" especially if your pre-amp has a selector switch specifically for mono? You should then have a dead centered image. How did you set the toe-in for your speakers, by eye? Try checking the toe-in with a laser pen or tool to get it exact. Maybe your eyes are lying. Best of luck.

You also want to make sure the recording you are using for reference actually has the vocals center stage. Many recordings, especially operas for instance, will place the vocalists all over the soundstage, for example, from standing just a foot inside or outside the speakers, to a few feet off center and dead center, actually anywhere inbetween the speakers and even outside the speakers, of course if your gear (and room) is up to that task.

From my experience, which goes pretty much along what is in the 12 page speaker setup manual that comes with Von Schweikerts (and similar SHOULD come with all big buck speakers, but many don't have more then a page of help):

-Toe in should be used more to lock in the 3D image, to obtain the most depth of the soundstage, the most body to sounds. The best way to do this is with pink noise, getting a phantom ball with 3 dimensions floating center stage much lounder then the faint fuzz from the speakers directly. Also worth note is that both speakers do NOT need the same to in angle, one can even be much further toe'd in then the other in order to create the best 3D image.

-The speaker distance relative to the rear wall (front/back) I would use for the 2D lateral imaging, locking in the center image, and the distance from the rear wall will affect 3D images, making the sound flatter if the speakers are too close, also greatly affect bass performance, of course.

-The speaker distance apart and from the side walls will greatly affect vertical imaging (rubber-band effect). Going too far apart and the stage will squish down, so keep moving out until the stage squeezes down, and don't hesitate to go a good 10ft apart or more with most speakers, even 15ft is not unheard of with great speakers The imaging as such across a huge stage is extreamely impressive! Personally, I can't stand to listen to speakers that are not at least 8-10ft apart, the overlap and lack of image specificity just annoys the heck out of me (yet, for whatever reason, 99% of dealers will set speakers 5-6' apart, where they sound like crap, and its hard to assess the virtues and vices of the gear...!).

This is just general info and there's much more to it, especially regarding room interactions (which make up for at least 50% of the sound!). There are plenty of books on the subject and many websites with info you can easily find, very good reading.

what speakers are you using? Have a pair of Martin Logan Quest Z speakers in system currently the Center image is very critical of the exact location of your head when listening if its not exactly centered the imaging is skewed especially the vocals

That's another problem I was thinking of but forgot to mention: Many speakers have a "head-in-a-vice" sweet spot, move your head an inch or more one way or the other and the magic is gone, the soundstage collapses. Such is the problem with the majority of time-phase aligned speakers, the sweet spot is the only sweet spot, sit anywhere else in the room and the sound is just mediocer at best, any other person listening is not getting 1/4 of the magic, although there are a few speakers that can offer a sweet spot as big as a sofa and the music will still be stunning even in a different room entirely....btw, did I mention how much I like Von Schweikerts? :o)