Kino Lorber 4K Blu-ray

Kino Lorber 4K Blu-ray

MGM Letterbox LaserDisc

The original mono mix has bad pitch and sound quality issues on the Shout! Factory Blu-ray and is terrible sounding. The LaserDisc PCM mono is very good but sounds a tad muffled in comparison to the MGM 2004 DVD mono at first listen. Yet the DVD mono has the volume of the entire track normalized so that effects and music remain at consistent levels which they don't in the LaserDisc mono-meaning that the jokes and gags hit harder in the LaserDisc mono because the mix varies as it was intended. It may be that the same source was used and then EQ'd and processed for the DVD boxset as all the mono mixes were messed around with. For example, when the hunchback disguise goes off with the explosions, the DVD mono has everything at a mostly consistent level. On the LaserDisc the effects build and fall off in loudness so the intensity is entirely different because they were mixed that way for comedic effect. Another is the piano smashing-on the DVD mono it's at the same level as the rest of the scene. On the LaserDisc it's loud and aggressively so which again makes the gag hit so much harder.
Again, the remixes are existing MGM ones and not good. The 5.1 remix on the Shout! Factory Blu-ray does not have pitch issues but the stereo remix does.

Criterion or StudioCanal 4K Blu-ray

Criterion 4K Blu-ray is SDR
StudioCanal 4K Blu-ray is HDR

The DV/HDR grade is tasteful and not overdone. SC has better compression, though not flawless; encoded by FiM, but Criterion also holds up quite well. Both releases claim to be approved by Lynch.

SC has a missing fade that Criterion reinstated.

Original matrixed Dolby Stereo mix: 2001 R1 Paramount US NTSC DVD/2008 R2 Optimum UK PAL or 1999 Pioneer JP LaserDisc

Restored stereo mix: Criterion / StudioCanal 4K Blu-ray

The film was originally mixed in Dolby Stereo (matrixed LCRS). For the 4K restoration, this mix has been transferred from the original magnetic elements and remastered with Lynch's supervision. Unfortunately, the fidelity suffered in the process, with many sections ending up significantly less detailed due to a noise reduction pass. This track has been altered compared to the original, with reverb added to some dialogue, different ambient sound effects, changed panning, and extended bass.

For the unrestored mix, there are two major options, each with its own merits and flaws. The 2001 Paramount DVD, which I would say is the best well-rounded mastering, and the 1999 Japanese LaserDisc, which has noticeably better clarity and high-end detail, as well as better dynamics, but suffers from occasional distortion and has less bass than the DVD.

The LD also has some ambiance buried too low in the mix, and some dialogue panned more to the centre than the DVD. There are no content changes I was able to find. Unfortunately, I don't know what accounts for those differences.

The other available tracks all have more significant flaws. The Italian and Japanese BDs use the same base mastering as the DVD, but with some patching in a few shots. HD-DVD is sourced from an inferior transfer, the same as the Momentum DVD.

The 5.1 remix, originally introduced on the 2002 DVD, and carried over without changes to the 2009 BD is a light and mostly faithful remix, with fairly minimal LFE and surround use, but still potentially worthwhile as the only discrete track.