The Wilson set up method (referred to in a previous response) is very good - we did mine using a laser range finder to arrange equal angles to each speaker and then calibrate the cant angle of the upper module (mid/highs) which is finely adjustable with my Wilsons. After all that I intentionally moved my listening chair around (after marking the original position) and wa interested to find that yes, as little as 6" shift was easily detectable by ear.
The Wilson method presupposes that having the speakers angled so as to point right at you is the way to go (I have no doubt that it is, for the Wilsons) but some speakers I have owned worked best pointing along the long room axis rather than at the listener, so preliminary experimentation by ear is called for if your speaker manufacturer gives you no guidelines.
The Wilson method presupposes that having the speakers angled so as to point right at you is the way to go (I have no doubt that it is, for the Wilsons) but some speakers I have owned worked best pointing along the long room axis rather than at the listener, so preliminary experimentation by ear is called for if your speaker manufacturer gives you no guidelines.