Comments

newhope wrote on 3/16/2009, 6:33 AM
You can during the render process chose to downmix the 5.1 mix to stereo in Vegas.
The function is accessed by a multichannel mapping checkbox... if my memory serves correct.
Check the Vegas Helps files for more info on this... I'm currently in Mac OSX so can't load Vegas to give more accurate details.

It doesn't do a bad job and I've found the resultant stereo file will decode into a pseudo Dolby Surround if fed through a Prologic decoder... note that isn't 5.1 but LCRS. It isn't a real Prologic encode but does add phase difference to the original surround channels of the 5.1 to send some of the audio to a rear channel of an LCRS system. I doubt this is intentional or controlled but I've certainly experienced it down mixng from 5.1 to stereo in Vegas 7

Strictly speaking though it is a stereo downmix not LtRt.

New Hope Media
musicvid10 wrote on 3/16/2009, 9:04 AM
I just render to one of the Stereo templates. This is useful for making an audio CD or files for portables, etc.

To preview a stereo downmix through your sound card from a 5.1 Project, there is a "Downmix to Stereo" button at the top of the Vegas mixer.

If I don't like the mix, I just change the Vegas Project Audio Properties to Stereo, then mix to my satisfaction, and render a new stereo audio file. I usually "Save As" a new Project so I have both at hand.

That being said, there is no need to do a separate stereo track if your goal is to make a DVD. The AC3 5.1 track contains all the tags necessary to tell the player to downmix to stereo (and quite nicely!), and also output for Dolby PL.

If you are interested in using the Dolby AC-3 Pro encoder rather than the Studio version (which has a couple of quirks), I have posted some suggested parameters from a previous thread:
"I've run some exhaustive tests with calibration test tones and done extensive reading of the Dolby metadata specs, and in reference to your question about the most accurate reproduction with the AC-3 Pro Encoder, I am prepared to make the following recommendations with notes:
Hope this helps.

Skaven252 wrote on 5/19/2009, 8:13 AM
I recently had a struggle with the issue. I had a 5.1 project and I was asked to do a stereo downmix of it. There was music (Left / Right channels only), speech (Center only) and sound effects (L, R, LS, RS, LFE). Each of these has its own bus (A, B, C), which are panned to their channels respectively, and the 'unused' channels turned off in each bus.

When I chose "Surround Master (downmix to stereo)" from the multichannel mapping options, for some reason the Speech track (Center) was dropped off - even if it can be heard in the preview.

Is there any way to render a stereo track "like you hear it in the downmix preview"?
Tslisher wrote on 5/20/2009, 12:10 PM
I believe that you can just select the downmix button in your Mixing Console window, then render to a stereo format using the 'render as' function under the filem menu and that will do it.

Most of the time however, I just adjust my project settings from 5.1 audio to Stereo (save as a new project), and then render out in a stereo setting. This allows you to tweak the mix a bit, especially in your case where you have seperated music and narration tracks.