Hi, hope you can help.
I recently set-up a Sony STR-DN1050 with mission surround sound speakers. In the set-up, the speaker test works perfectly.
I've then connect my Smart TV to my computer and I can successfully play video files and hear the sound, but it's not coming through as surround sound. I am playing files that have been encoded as AC3 which I believe means they should play as surround.
AC3 (also known as Dolby Digital) can have only 2 channels.
If the TV gives you digital surround on other sources (the front panel of the receiver usually will indicate that) then the TV audio settings are correct. If not then change those settings.
A lot of movies that are streamed or downloaded have the multichannel audio removed to allow for smaller file size or more reliable streaming.
If you select Dolby instead of auto for that input (as your surround mode) the receiver will default to Dolby Prologic2 (when it receives a stereo input) which will give you analog surround sound.