[William Sommerwerck]

Incidentally I have never heard a widening effect that
actually gave a stable image outside the speakers.
They only ever sound vaguely as if the speakers are
wired up wrongly -- not at all satisfactory.

As I said in a preceding post, there are forms of processing that place
sounds "outside" the speakers. (These are used mostly to get surround effect
from two speakers.) They work very well, and don't sound "phasey". However,
the effect is not stable with large head movements.