I've lately been interested in how 5.1 home video audio mixes across various formats compare to their theatrical counterparts. So I've taken the cinema DTS tracks that I've been able to find or that others have kindly shared with me and done some visual waveform comparisons.
All cinema DTS tracks have had their surround channels attenuated to -3Db and LFE channel boosted +3Db for pre-1999 movies and +6Db for post-1999 movies. For more information on why this is necessary see this wonderfully informative thread by pipefan413.
So I'll start with The Matrix.
The Matrix - 1999 Theatrical DTS 6-Track
So here's the cinema DTS. It's a very dynamic mix with LFE and surrounds used fairly sparingly until the final 30 minutes of the movie.
The Matrix - 1999 DVD - AC-3 5.1 448kbps
The DVD release is not as dynamic as the theatrical DTS. Adjusted for volume the centre channel has a slight boost and LFE + surrounds have been toned down. It looks fairly close to the theatrical mix though.
The Matrix - 2008 Blu-ray - TrueHD 5.1 1646kbps
Once adjusted for volume this is essentially just a less dynamic rendering of the theatrical mix with LFE toned down a little. It's very close indeed. It could even be that these are near-field adjustments intended to recreate the sound of the theatrical DTS in a smaller space - I don't know enough about this to be able to say.
The Matrix - 2008 Blu-ray - AC-3 5.1 640kbps
I'm not even sure why this track is on the BD. The TrueHD has an AC-3 Core track for compatibility so this seems utterly redundant. This one is an even more neutered version of the DVD 5.1. The centre channel dynamics have been squashed even further and the LFE in the finale has been toned down yet again. Worse still, this is the default audio track on the disc so the vastly superior TrueHD track has to be manually selected.
The Matrix - 2018 Ultra HD Blu-ray - TrueHD 7.1 4868kbps
Unsurprisingly the Atmos track on the UHD is a total remix with lots of additional LFE and boosted surround effects. From an authenticity standpoint, it has no value whatsoever.
The Matrix - 2018 Ultra HD Blu-ray - AC-3 5.1 640kbps
Anyone hoping that the 5.1 track on the UHD was the original mix is going to be disappointed. It's just a 5.1 channel folddown of the Atmos remix with a boosted centre channel.
Missing Mixes
Not included in this comparison is the LaserDisc AC-3 simply because I don’t have it though I've heard it's the same as the DVD 5.1. If anybody has it and would care to share then I’ll gladly add it here.
Conclusion (TL;DR)
The BD TrueHD 5.1 looks to be a very respectful attempt to create a slightly more polite rendering of the theatrical audio track. Anyone who maligns the BD 5.1 for being nothing like what they heard in the cinema in 1999 either has very keen ears or went to the wrong cinema.
More comparisons to follow.
All cinema DTS tracks have had their surround channels attenuated to -3Db and LFE channel boosted +3Db for pre-1999 movies and +6Db for post-1999 movies. For more information on why this is necessary see this wonderfully informative thread by pipefan413.
So I'll start with The Matrix.
The Matrix - 1999 Theatrical DTS 6-Track
So here's the cinema DTS. It's a very dynamic mix with LFE and surrounds used fairly sparingly until the final 30 minutes of the movie.
The Matrix - 1999 DVD - AC-3 5.1 448kbps
The DVD release is not as dynamic as the theatrical DTS. Adjusted for volume the centre channel has a slight boost and LFE + surrounds have been toned down. It looks fairly close to the theatrical mix though.
The Matrix - 2008 Blu-ray - TrueHD 5.1 1646kbps
Once adjusted for volume this is essentially just a less dynamic rendering of the theatrical mix with LFE toned down a little. It's very close indeed. It could even be that these are near-field adjustments intended to recreate the sound of the theatrical DTS in a smaller space - I don't know enough about this to be able to say.
The Matrix - 2008 Blu-ray - AC-3 5.1 640kbps
I'm not even sure why this track is on the BD. The TrueHD has an AC-3 Core track for compatibility so this seems utterly redundant. This one is an even more neutered version of the DVD 5.1. The centre channel dynamics have been squashed even further and the LFE in the finale has been toned down yet again. Worse still, this is the default audio track on the disc so the vastly superior TrueHD track has to be manually selected.
The Matrix - 2018 Ultra HD Blu-ray - TrueHD 7.1 4868kbps
Unsurprisingly the Atmos track on the UHD is a total remix with lots of additional LFE and boosted surround effects. From an authenticity standpoint, it has no value whatsoever.
The Matrix - 2018 Ultra HD Blu-ray - AC-3 5.1 640kbps
Anyone hoping that the 5.1 track on the UHD was the original mix is going to be disappointed. It's just a 5.1 channel folddown of the Atmos remix with a boosted centre channel.
Missing Mixes
Not included in this comparison is the LaserDisc AC-3 simply because I don’t have it though I've heard it's the same as the DVD 5.1. If anybody has it and would care to share then I’ll gladly add it here.
Conclusion (TL;DR)
The BD TrueHD 5.1 looks to be a very respectful attempt to create a slightly more polite rendering of the theatrical audio track. Anyone who maligns the BD 5.1 for being nothing like what they heard in the cinema in 1999 either has very keen ears or went to the wrong cinema.
More comparisons to follow.