The Great Dictator (1940)

Criterion booklet:

"The monaural soundtrack was transferred at 24-bit from the sound negative and restored by L.E. Diapason using Pro Tools and Cedar. Additional restoration was done at Criterion, where clicks, thumps, hiss, and hum were manually removed using Pro Tools HD and crackle was attenuated using AudioCube's integrated workstation."

Once again, this 'additional restoration' was completely unnecessary, and has done far more harm than good. The film's extreme low frequencies have been removed non-selectively, and planes (especially) sound weaker. However, hiss/noise reduction of the high frequencies is the bigger problem, since all dialogue now sounds more muffled and the opening credits' fanfare loses a good chunk of its brassy impact. The Criterion just has a 'dead' quality to it.

My point of reference here is the English mono track from the German Kinowelt blu-ray. It has the full frequency range of L.E. Diapason's restoration seemingly intact. But, it seems Kinowelt applied some compression to the track during authoring.

In my book, compression is a lesser evil than noise reduction, especially when it's this light. (Anyone who disagrees probably hasn't volume-matched both tracks properly -- the Kinowelt is several dBs louder, and a negative gain must be applied to compare it!) You should know, too, that zoomed-out waveforms tend to make any amount of dynamic range compression look worse than it actually is.

Still, I'm hoping one of the MK2, Park Circus, or Artificial Eye blu-rays will be free of both problems.