Watership Down (1978)

The 2008 Deluxe Edition DVD, the Criterion blu-ray, and the UK Universal blu-ray are all sourced from the same audio master. The original DVD is much better sounding and was definitely derived from the same analogue source, which the Criterion booklet identifies as "a 35mm magnetic track".

The former three discs sound basically the same. The latter (earlier DVD), though, has a wider soundstage, with the dialogue being far more directional. The soundstage has been narrowed on the later releases. The original DVD appears to be a straight transfer with no high-frequency attenuation at all (it sounds phenomenal), while the others have a fair bit of noise reduction applied.

The Warner LaserDisc actually has a slightly wider soundstage than even the original DVD, but its high frequencies are rolled off and so sounds quite a bit less clear than the original DVD.

When listening to the following comparison clip, listen for 1) the noise reduction on the blu-ray track (which can be heard in the absence of ambient detail and the dullness of the strings in the score); and 2) some of the dialogue being placed more to the sides on the DVD but centered on the blu-ray.

Update (13/05/2018): German blu-ray added; unsurprisingly, it sounds the same as the other blu-rays.