Don't Look Now (1973)

The old Optimum DVD (no spectrals) sounds horrible--severely filtered and quite possibly from a high generation source. The Studio Canal blu-ray sounds similar: very little detail, an unnatural vocal timbre mucking up dialogue, just bad. 

The Paramount DVD sounds much, much better. Lower generation source, significantly more detailed, high frequencies mostly intact. Its low frequencies have been removed a bit too aggressively, however, probably because it seems the original sound negative (or whatever elements were used for the Paramount DVD and the below blu-rays) has some minor low-frequency hum here and there, louder in some scenes than in others.

The Criterion BD also has its low frequencies attenuated. The Optimum and Criterion BDs are sourced from the same A/D transfer, the latter a further filtered version of the former. I prefer the Optimum. It has some minor rumble issues, but these are too faint to be intrusive, and boats, fire, and other bassy sounds sound better. It also has less high-frequency NR and consequently consistently more high-end detail. As you can see in the spectrals, the segment ~30 minutes into the film on the Optimum blu-ray has more high-frequency information than any other part of the film -- this is the sex scene. I'm pretty sure these frequencies were left intact here in order not to harm the delicate piano/flute instrumentation during this scene, which sounds a lot more detailed than on the Criterion track.