I have a 5.1 source on a laptop which I connected to my tv through hdmi (it downgrades it to stereo—does it throw away the extra channels or put them into the front channels?) which I connected through stereo RCA cables to my home theater sytem which then gives me "fake" 5.1. Is there anything I can do to improve this? When watching movies I either get almost nothing in the rear speakers or too much and all I get out of surround tests is an echo.