Jeff, you haven't described your listening position, but there's no good reason to mention anything other than the general rule of separating the speakers by about as much as the distance you are from them.

As far as the next upgrade, if you're going to stay with a stereo setup that pretty much limits it to a sub. The low bass can certainly be important in some music, so no, a sub isn't just for explosions in movies.



-----------------------------------

Enjoy the music, not the equipment.