Matrix meets some of the loudness war.
The Atmos track has more dynamic range compression and peak normalization applied in comparison to the original Blu-ray DTHD 5.1 track, increasing the overall track level and pushing transients closer to full scale.
I did extract the included DD 5.1 track but eac3to claimed detecting some clipping and reduced the gain by -4.29dB. The resulting waveform looks much closer to the Atmos 7.1 mix than the original Blu-ray DTHD 5.1 mix. I am not including pictures of the DD at this time. I might try again with the original DVD's DD track.
The DTHD LFE channel does not have a lowpass filter applied whereas the Atmos and DD LFE does.
Dynamics have been reduced in addition to the differences to levels, EQ, channels and objects of the Atmos mix, resulting in material sounding much more forward or peaking unnaturally with the squashed transients. Or as many have expressed "more revealing".
The Center channel has more peak normalization and compression in the Atmos track versus the DTHD, approximately 3.17dB difference, while the later does have a minor instance of clipping it is overall more dynamic.
*I need to do some more listening comparisons between the Atmos and DTHD tracks to determine if the bass is actually improved and has more content with the new mix or it is the same material but simply louder . I'll update my comments later.
**After further demoing some material from the first six minutes there pros and cons for each mix. The Atmos does have more bass, some of the emphasis has been mixed into the main Left and Right channels more than the DTHD track. LFE in the Atmos mix does have on the whole dramatically more output. Yet, one can have too much of a fun thing.
This is not the worst remix I have heard nor the loudest but at least to me the mix would have benefited from being a little less aggressive in elevating the levels. The sound design has always had a pumpy quality to many sound effects, which further stands out now in the Atmos mix. While the bass has been improved it also can be a bit too much.
For those that appreciate those qualities then the Atmos mix is a great improvement, while those that may prefer an alternative will find the DTHD a bit lacking in the bass department after listening to the Atmos mix.
Matrix 4k Atmos 7.1
ITU-R BS.1770-3 Loudness: -15.69 LUFS
Matrix original Blu-ray DTHD 5.1
ITU-R BS.1770-3 Loudness: -18.53 LUFS