[Archguy]

ATM I'm listening to Donald Byrd's "Here Am I" and the trumpet it clearly coming from well to the left of my left speaker.  The sax, piano, percussion and bass are all coming from within the apparent soundstage, that is to say generally within the range of the two front speakers.  But the trumpet is clearly outside of it.  This isn't even possible, is it?

I have an auxiliary 'fill' pair behind my listening area.  I presume this is the cause?  Whatever it is, it's cool. 

[Letitroll98]

This is quite normal for a stereo pair of speakers without any rear or side fill speakers.  It's something to do with the signal being out of phase, I can't remember the exact causation.  For example of an extreme case Sting's album, "The Soul Cages" has sounds coming from 90 degrees to the side using this technic.  How far beyond the speaker's boundary the image carries is one of my criteria for music and speakers.