As I say in an other thread, there is a problem with channel assigment of audio 5.1, not the same between AAC and AC3 output.
After a lot of tests, I have understand the problem :
Adobe change the 5.1 channel assignment during import and on time line since version CC2014.
It was L, R, Ls, Rs, C, LFE, in versions CS6, CS7
It is nows L, R, C, LFE, Ls, Rs in newer versions
With voukoder :
Export/Import in AAC format conforms to these spécifications
Export/import in AC3 only conforms to CS6 spécifications, it is wrong in later releases.
I have make a clip with music only on suround channels, and audio recorded on front channels
Images attached shows the layout in source monitor (same as timeline)
Please check this (with the other clip provided in zip) and
as voukoder is now the best way to export to AC 5.1, thanks in advance to provide a correction.