Much has been said elsewhere about the need for quality sources when doing upmixing. Sure about anything from low rate MP3 to high bit/sample rate can go through a a PC upmix program or Surround Master, etc & give some of surround sound field. I've re-discovered a dts white paper on my HDD that explains quite well why this is, or at least another aspect. Like a lot of white papers it is ther to show dts Neural Upmix superiority it has some good insights as well.
Me thinks the paper is long gone from the dts site so you can grab it here on Dropbox.
Me thinks the paper is long gone from the dts site so you can grab it here on Dropbox.