THX-Mastered was a home-cinema buzzphrase in the late-90's/ early-00's that guaranteed the audio-visual (or 'audo-visual' as Q termed it in Goldfinger) content was the best quality that the state of the art(s) could deliver for the format.
The 'THX' part of the moniker was both an acronym for, "The Tom Holman Xperiment", and also the first half of the title of George Lucas' first commercial foray into science-fiction, THX-1138.
THX was a quality-assurance programme developed by George Lucas' Lucasfilm to ensure the best possible cinematic experience. Projection, loudspeaker and audio processing equipment could be THX-certified if it met stringent benchmarks as set by Mr Lucas. The success of the THX-certification programme for cinema prompted manufacturer's of home-cinema equipment to press for the THX programme to be extended to the consumer environment; as a consequence, myriad home-cinema kit bearing the THX logo began appearing in the marketplace. The next logical step was THX-certification of movie software, and LaserDisc (LD) was a perfect candidate.
As a consequence, the first THX-certified 007 title, GoldenEye, was issued in 1997; followed by six back-catalogue titles in 1998:
Dr. No (DN)
From Russia With Love (FRWL)
The Spy Who Loved Me (TSWLM)
Curiously, the LD of Tomorrow Never Dies, also released in 1998, did not receive THX-certification.