bwtr, I'm not quite sure what you're asking. It is possible to have sound in an .avi file, it's just that for some reason Carrara won't do it. If you want to use Carrara to add the sound you'll have to use the .mov format and then use a program like Quicktime Pro to convert to avi. Alternatively you could add the sound separately in a video editor. For the best compression the new Quicktime H264 codec takes a lot of beating. To get that you'll need to download Quicktime 7.