Trying to get Sound Stage with Klipsch Tower Speakers

I have Klipsch RP-8000F speakers and do not get decent soundstage.  The vocals seem well-located between the speakers.  I have paired subwoofers for bass, and therefore no problem.  Piano, violin, brass seem to emanate from either the right or left speaker.  I've tried toe-in and varying speaker position without success.  In my other system I use KEF LS50 Meta's and the superiority of soundstage is stunning.  I would appreciate all helpful suggestions.