Newbie here so sorry if it's something simple. Currently I rip my movies to mp4 using the generic.mp4.h264.aac profile. The reason for this is I have a lot of movies but not a lot of hard drive space to store them. I use a Control4 media player to play the movies on my 50" TV and I care more about the quick access to them that I have then the quality and so that's again another reason why I use mp4. However I just noticed that even though I select the AC-3/5.1 audio, I'm only getting stereo playback. What do I need to do to get multi-channel audio while still keeping a small file size?