dts neo 6

after putting new Morrow MIA interconnects tween my Sunfire TGPIII and symphonic ref amp, I was trying out sound modes, and stumbled onto DTS NEO6,

even tho only set up for stereo, hooked to Vandersteen 2Cis, and the TGPII set at no center, sides or surrounds,
the DTS NEO6 sounds great,
it makes PLII and source direct sound muffled.

why or what am I hearing?