free advice, maybe worth just about that much.
i've found remarkable difference in sonics in moving my GS 10s
to different positions. move them about 2 or 3 feet from rear wall,
and the base is less, but much more articulate and tight. move them from
side walls, another very different ( and for me, pleasing ) sound.
i suspect it depends on the various qualities of the room in question,
and the electronics precediing the speakers, but i encourage you to try moving the speakers away from the rear wall particularly,
and see how they strike you.
i got much more variation in sonic qualities by moving the speakers
around, than i did changing cable. but again, just my particular experience.