If you save it with exactly the same file name as the MPEG-2 file, except with .ac3 as the extension instead of .mpg, and save it in the same folder, DVD Architect will include it automatically when you select the video file.
If you've already started your DVD project and included the .mpg file, you'll have to open up that media selection and manually drag the .ac3 file onto the timeline right beneath the video.
i took a vhs and clipped it into seperate mpg's. if i take that mpg and open it in soundforge 6, will i be able change to .ac3? what about the mpg audio can how do i get rid of the file for more dvd space. shoul i render the audio and video seperate?