P.S. As Rodman99999 stated, azimuth also affects timbre. Signals that come from one source (speaker) only will be phase coherent (assuming decent speakers). If the signal bleeds into the other channel due to crosstalk from incorrect azimuth, the same sound coming from two sources (speakers) is highly likely to be phase incoherent... ie, muddy sounding.
This is easy to hear but perhaps more difficult to use as the basis for adjusting azimuth, at least IME.
This is easy to hear but perhaps more difficult to use as the basis for adjusting azimuth, at least IME.