(2021-01-05, 02:04 AM)Plissken1138 Wrote: I didn't know, I just assumed it should be. It does sounds great, just doesn't sound much different from DTS-HD MA 5.1 Mix. I was expecting it to go through four speakers
Thanks for reminding me of that thread. I started to read at one point but being a complete noob it quickly went into that gif with flying math formulas around my head 
I'll give it another go.
Definitely understandable, some of this stuff is really really poorly understood by most (including me half the time) because it's really really poorly documented/explained to the consumer. Boxes frequently have incorrect specs on them, and even when they're correct, they usually aren't actually helpful; so yeah, you might have a "DTS-HD MA 2.0" track, but is it designed for playing through two speakers? Almost never! (More commonly with TV stuff or music-orientated releases, but with films 2.0 is almost always "dual mono" or a Dolby-style matrix-encoded 4-channel mix that's been condensed down to 2 tracks for practical reasons.)
For the same reason I can understand "stereo" or "2.0" sounding like "front two speakers" when it isn't, I can very much see why in general one might assume "4.0" to mean "four equidistant speakers". But when it comes to film, specifically, that's not the case.
It's all a bit of a faff, let's be honest. But I find it very interesting, all the same.
And yeah, it'd make sense if the 4.0 doesn't sound all that different to the 5.1 because the 5.1 will have been made from the 4.0. If you start with 4 channels - Left, Centre, Right, and Surround - but work on the basis of most home surround setups having two (rather than one) surround speakers, you'll want to turn the Surround channel into Left Surround and Right Surround. So we're at 5.0. Quick low-pass filter separates out your LFE for the subwoofer (".1" since it isn't a proper full bandwidth channel) giving 5.1. They may have, and quite possibly did, do some amount of remixing and fiddling, but that's more about making the 5.1 mix sound subjectively "impressive" than it is about making it sound how it did in the cinema. One hopes the 4.0 track is relatively close to a discrete version of the actual Dolby Stereo cinema track, and if it isn't, then it doesn't really matter because the actual Dolby Stereo mix is presented as "2.0" on the same disc, so you can pass that through your decoder to split it back up into multiple channels again that will still give you a surround experience... very much as a cinema Dolby decoder would have originally.
