Mods, can you move this to the right section, sorry, I goofed.

There are many audio tracks from LDs that have to be filled in with alternate sources of the same audio to be able to sync to a BD release…

I need some pointers. I have LD 2.0 Stereo PCM audio that I must fill in a very small part of and I only have a 5.1 DTS-HD source for filling it in, what is the best way to downmix the 5.1 DTS-HD to 2.0 Stereo PCM without losing anything in the process?

Also, what do I do if both sources are different volumes?