Well, 5.1 audio is easy. 5.1 is 5-channel sound -- two speakers behind you, two main speakers in front of you plus a sub-woofer. In order to create true 5.1 audio, you need to mix all five channels of sound, and your original video needs to have been recorded in 5.1 audio, so very few people are creating 5.1 audio home movies.

But CyberLink's True Theater sound is supposed to create the effect of 5.1 depth on a stereo system. How it does this I don't know for sure, and the Help files don't offer a lot of details. But that's what the marketing page says.

Quote Hello,
When I choose the TrueTheater surround while producing a mp4 file, the result is a stereo file.
In order to get 5.1 surround I have to choose AAC 5.1. The DTS 5.1 can't be choosen.
By the way, what is the difference between those three?

I actually have freemake video converter and you can decode AAC 5.1 into Dolby Digital 5.1 ...Now it takes a few hours to convert due to how many gigs the file is and also you're not only converting the audio but the video as well . I just converted The Night House ,Malignant with stunning Dolby Digital... Just a thought if someone would like to try it ...Freemake does cost i'm not sure what the price is now since i've had it for serveral years now.

Being a newbie to this program but having worked with Vegas and Magix Pro before, I think the following applies, based on experimenting with Cyber Director:

The True Theatre Sound option on my very expensive HIFI provides a somewhat muffled result compared to two channel stereo. The reason I speculate is, it does put the sound on all channels however adds a delay or echo to enhance this to a pseudo surround - making the sound to me less optimum (I tried mixing music videos).

As to true surround I am not sure if this can only be properly achieved in conjunction with their Audio Director365. According to their website it even manages to mark objects in Power Director and make the sound follow.

However this is only available with those features, as I understand it, if you make one of their monthly subscription schemes.

I feel a little disappointed and dazzled as I opted for Power Director BECAUSE I finally wanted to make 5.1 Videos and feel a little cheated. But maybe I am just not familiar enough with the programm, however can't find anything in their online handbook either contradicting me.