When I listen to an uncompressed soundtrack through PCM, is it the same as DTS-MA through bitstream?
First, PCM is uncompressed, so you can’t really listen to uncompressed sound through PCM. PCM, Dolby TrueHD and DTS-HD MA are lossless, which means there’s no loss in sound quality from the studio masters. Dolby TrueHD and DTS-HD MA are compressed, which means they take up less space than PCM on the disc. Now, when you listen to a TrueHD or DTS-HD MA track, it gets converted into PCM (either in the player or in the receiver/preamp). So, technically, there shouldn’t be a difference at all, considering they’re all lossless, and by the time the signal gets to your speakers it’s all the same thing. However, because the tracks are encoded differently, the mixers (or authors of the disc) might tweak sounds a bit. For example, in the Flash Point BD, there’s a PCM 7.1 and a DTS-HD MA 7.1 track. They’re essentially the same, only the PCM sees to be more bass-heavy, whereas the DTS-HD MA track is a bit more open in the high-end. Unless you have a good system, you wouldn’t notice the difference.
