Come and See (1985)

I haven't level-matched the waveform images as I normally do, since some of the tracks have noteworthy volume discrepancies between their channels. However, the spectrals and frequency line graphs are volume-matched at 1 kHz, as I usually do. PAL speed-up was removed from the tracks that have it, and the IVC blu-ray was pitch-corrected. For the sake of easy comparison across images, I've duplicated the Criterion 1.0 track to two channels and I've separated the three main channels of the Potemkine into C-C (the centre channel duplicated) and L-R (the left and right channels combined into one track). 

2001 Kino DVD: This is a PAL-to-NTSC conversion, so its audio track has PAL speed-up (both tempo and pitch). After correcting its channel imbalance (the left channel is 5 dB too loud relative to the right), it's still obviously stereo. It's a discrete remix with new sound effects and a fair bit of noise reduction.

2004 Close-Up DVD: The 2.0 track on this disc is mono, but it's a downmix of the remix that appeared on the Kino DVD. It has PAL speed-up (tempo and pitch).

2019 Mosfilm YouTube stream: I've provided this as a reference. Its EQ is the same as all the blu-rays and it confirms that none of the blu-rays have additional hiss reduction. I think it's safe to assume that this and every blu-ray contain the theatrical mono mix (or derivations thereof - see below). It has PAL speed-up (tempo and pitch).

2016 IVC blu-ray: Although this disc plays at 23.976 fps, its audio track is pitched 0.7 semitones too high. It sounds quite good otherwise, but it has significant clipping (like so many other IVC blu-rays) and so typically sounds duller. If you compare its frequency line graph to the Criterion's, it's evident that low and high frequencies are less abundant, which is consistent with the omnipresent clipping. This audio track is definitely sourced from the same materials as the later blu-rays--and may indeed be the same transfer--and so possesses similar detail despite the video being a scan of higher generation materials.

2019 Potemkine blu-ray: This disc has a 3.1 track derived from the theatrical mono mix. The left and right channels take the old 'odd frequencies in one channel, even frequencies in the other' approach to faux-stereo. The LFE takes its low-frequency information from the other channels. When isolated, the centre channel sounds good, though it's missing some bass information.

2019 Lumière blu-ray: The 2.0 track here is the mono subjected to the same process as the left and right channels on the Potemkine, but more subtly. It's difficult to discern that it's now technically stereo.

2020 Bildstörung blu-ray: This track has odd recessions in frequency response across its entire spectrum that aren't really audible. Both channels are identical. 

2020 Criterion blu-ray: This is the best version among all of these. While none of the blu-rays sound bad per se (no noise reduction, bad EQ, etc.), the Criterion blu-ray's audio is the only track that's true mono, unclipped, and free of other technical issues.