Help with Explorer 8300 Cable Box

Can anyone help me with what their recommended settings are for this cable box (I think the full series is Explorer 8240 HDC)? What I have seen so far with my set up (using HDMI to a 42D64U) and optical cable to an Onkyo receiver, but the PQ from my channels is not all that impressive, and I can't seem to find the settings or set up that will give me the best results (they did not give me a manual either)


I am still new to the HDTV world...can anyone give me some tips? Thanks