I'm not sure what speaker system you have. I would try repostioning your speakers first. One method I have used with my Revels, is to mount a laser pointer to a yard stick and use it while following Newbee's advice above. The laser pointer is a bit more precise and if you use one of the newer ones that emits a line, even more effective. I've found the more precise you are the better the image quatlity. Also make sure to level your speakers left to right. If your speakers can be adjusted vertically to increase/decrease the tilt, that can help too. You might want to experiment with widening the distance between your speakers and nearfield postioning.
If you have not done so finding and treating the first reflection points can sometimes widen the listening sweetspot. You may want to use some diffusion.
Hope this helps.
If you have not done so finding and treating the first reflection points can sometimes widen the listening sweetspot. You may want to use some diffusion.
Hope this helps.