I have a project for which I rendered a video only stream and a 5.1 ac3 soundtrack for.
The project properties were set to ac3 STEREO when I added the video and audio streams. The disk space estimate was 6.2 GB when I first added the audio track to the project.
When I changed project properties to 5.1 ac3 audio, the estimate changed to 4.7 GB, more like what I expected.
Then when I changed it back to ac3 stereo, the disk space est went to 4.5 GB, again more like what I expected.
The project properties were set to ac3 STEREO when I added the video and audio streams. The disk space estimate was 6.2 GB when I first added the audio track to the project.
When I changed project properties to 5.1 ac3 audio, the estimate changed to 4.7 GB, more like what I expected.
Then when I changed it back to ac3 stereo, the disk space est went to 4.5 GB, again more like what I expected.