Hi MR! I have searched all over the internet and keep coming across various opinions and I am getting very confused. I have a file that I would like to play on my ATV2. Currently it is a mkv with a ac3 6ch soundtrack. I have used MKV tools to convert this to a m4v with AC3 5.1 . I then put it in subler to add metadata and it shows that it is a ac3 6ch track still. When it streams to my ATV2, my amp shows sound is coming from all of the speakers which it is. Is this the best way to go or should I use the AAC 5.1 option? Sorry if this has been covered a thousand times, but the posts I read contradict each other and confuse me.