Cam,
Move forward with the six or eight (try them both). Don't worry about the seemingly feeble sub output. I had the same thing happen on my EP500 (using 3808 as well). The *only* thing I did after running 6 positions was to change the main speakers to small. I left everything else alone including the crossover settings. I can *ASSURE* you that my EP500 nearly knocked the wall down when the THX demo scene came out on the INDY4 Blu-ray disc.
For me, six positions were much better than eight. With eight positions, the center sounded muffled and the bass was very boomy! The CBS/FOX NFL shows with the constant "swhoosh" sounds on intro's nearly killed me. But now, it sounds PERFECT.
