Plex for WebOS always uses the first audio track, which is AAC stereo in the Apple TV presets of Handbrake. The second audio track is AC3 Dolby Digital and often contains discrete multi-channel audio (e.g., 5.1). Right now, if one wants to use this second audio track it has to be manually selected during playback.
My request is that the devs enable Plex to choose the AC3 track if the sound is generated by an appropriate receiver (e.g., 5.1 receiver connected to the TV via HDMI or Toslink optical cable). Plex Home Theater (deprecated), OpenPHT and Plex Media Player each do this, and have for many years.
I believe what you’re looking for is already addressed in an existing feature suggestion. If so, I’d like to ask you to comment/vote in that thread in order to avoid distracting/dispersing votes and attention.
This strategy will go wrong if you encounter a movie which has the main movie sound in stereo or mono (beause it is an older title) but has a commentary track in AC3.
Otto, the Handbrake presets use track 1 of the source file to generate both the AAC and AC3 files. If track 1 in the source is already AC3, then it sets it to passthrough in the m4v container that is generated (i.e., AAC stereo as track 1, AC3 passthrough as track 2).
