MP4/6 channel AAC ---> MKV/6 AC-3 ?

[NotSoEasy]

I was using Mp42Mkvac3 but it's not very stable as many files you input wont convert, many wont unless you 'shorten' the file name.
I do not own a PlayStation so I have no way to decode the AAC and all I get is Stereo 2/channel sound.
What other ways can I change the container (if I even need to) and mostly, change the audio to 6 channel AC-3

[jman98]

The following article covers your question and hopefully has a method that will work for you.
https://forum.videohelp.com/threads/337053-How-to-convert-AAC-to-AC3

I prefer not to deal with AAC audio whenever possible so I have no experience doing this, but hopefully the article in the link can help you.