"We thus find that the majority of laserdiscs and DVD’s are labelled THX. These laserdiscs and DVD’s have absolutely nothing more than the others: neither supplementary track nor special encoding. They simply guarantee that the image and sound are of optimal quality, in such a way as to allow you to get the best from your system. We have also seen video cassettes with the label. In fact, as long as there will be sound/video supports, the THX label will be there to guarantee the quality of the contents.
In a similar logic, it would not impossible to one day see THX television programmes, because in absolute terms, the quality norm could also apply even to sound recording in the TV studio or optimal lighting in order to obtain the best image.
Please note that it is not because a laserdisc, DVD or cassette do not have a THX label that it is not worth watching! Most laserdiscs and DVD’s manufactured are extremely good, not to say exceptional. They sometimes even go beyond the specifications outlined by the THX norm, but the manufacturers simply don’t see the need to label them, whether it be for ethical reasons or due to budgetary restraints. The THX label as well as its licence cost a certain amount, and certain publishers choose not to pass the cost on to the consumer through their products. An example is the excellent "CRITERION COLLECTION" in NTSC."