surround sound help...

[davew1]

hi all. just bought a samsung ht-e4500 surround sound system. set it up with digital optical cable from duo direct into it.
i've read that to get 5.1 sound i need to turn digital downmix off. however when i do this i then get no sound at all from any speakers. when i turn it on i get sound through them all. have i set something up wrong? am i getting some sort of weakened surround effect while digital downmix is on?
i'm using vix 3 build 249. hope some1 can help

cheers, Dave

[Maxwell]

when you switch downmix to off it changes the output to bitstream - you have an incorrect setting somewhere on the Samsung unit which is why you hear nothing

[davew1]

Cheers Maxwell you were right. went into the audio settings on the sammy and seen the audio return channel (ARC) was switched on so was listening to the tv sound through the hdmi instead. :o