Are you saying if a disc has a TrueHD/Atmos soundtrack, it must also have an entirely separate DD 5.1 soundtrack? That's very odd and entirely unnecessary given the True HD will play perfectly well in 5.1 and sound a lot better too due to being lossless. Do you have a reference for this requirement?
Ah wait, it's got nothing to do with it being Atmos. It's because True HD has no fallback for old amps that can only take audio over coax or optical, they need a DD 5.1 soundtrack to play. DTS HD MA and DTS:X can output the DTS core that is within them, but Dolby True HD has no equivalent.
It won't play perfectly well on equipment that doesn't support True HD. In most cases the disc player will send signal over an HDMI connection, leaving the decode for the AVR, which might only support DD.
I got confused by Atmos, which this has nothing to do with.
Dolby True HD is an optional format on Blu Ray, players don't have to support it. But support for Dolby Digital is mandatory, so a disc that has a DD 5.1 and True HD is guaranteed to be able to play on any player.
Seems likely, I can't imagine anyone wants to mix it separately doing a load of work for a DD 5.1 soundtrack that almost no-one will ever play.
The DD track on Goats Head Soup was different, if I remember correctly.
So if you play the Atmos track on a 5.1 system - I imagine it is just folded down. I'm no mixing engineer, but the 5.1 mix on most of these albums is a DTS-HD mix - so I presume it is not the same? I am almost certain it is a unique mix. In some cases, like Fish's 13th Star, people have been remarking that the 5.1 mix is even significantly different (in that case specifically, much worse).
For the John Lennon “Gimme Some Truth” Atmos collection there were some complaints that the mixing of the TrueHD Atmos track was too loud (loudness wars style). In a sort of happy accident, the DD5.1 mix was not affected, so it was separately mixed (or minimally mixed).
Ron, thx!
So just to confirm, I think there is:
1. Original 1973 stereo mix released many different times on LP & CD as various different masters (I think I have the original CD master, the 1994/5 remaster and the 2011 remaster (both in 44.1/16 & 96/24), and now the 2023 "50th anni edition" remastered at 192/24 (for BluRay and streaming) and 44.1/16 (for CD and streaming)) - I further wonder if the 44.1/16 2023 remaster is a "dithered" 192/24 -> 44.1/16 or a "proper" 44.1/16 remaster?).
2. Original 1973 stereo mix, remastered in 2003 by Guthrie for SACD (both for the PCM AND DSD stereo parts of the disc, whilst also doing the DSD hi-res 5.1 remix and master)
3. Original 1973 stereo mix, remastered in 2011 by Guthrie for the 2011 Immersion set on CD (44.1/16) & BluRay (96/24)
It's confusing when various resources describe a new remaster as a remix as you say, the stereo has never been remixed, but has had umpteen remasters!
How close to getting all that correct was I?
You can almost certainly select the DD 5.1 track using the Audio button on your player's remote, I recall seeing the extra DD 5.1 track there on a couple of discs.
Any disc encoded using lossless Dolby TrueHD with or without Atmos must have a lossy Dolby Digital 'core'. It's a mandatory requirement of the Blu-ray disc specification.
There is no DD 'core' with Dolby True HD, it's a completely separate soundtrack.
Probably through a valve amp stage if James Guthrie did it...
Every Blu-ray disc that has been encoded with Dolby TrueHD (with or without Atmos) has a Dolby Digital core. Look in the .m2ts contained file.
I’ve seen this turn into arguments before, so I’ll throw in my two cents. The terminology for the required DD track is often referred to as a “DD core” but it is technically a separately encoded stream from the TrueHD track that could even be a different mix. The TrueHD and DD tracks are combined (maybe where the term “core” comes from) and need to be demuxed to ascertain the differences. See my John Lennon’s Gimme Some truth example above.
