THX began life as part of LucasFilm. The initial goals for THX was to ensure that movie audiences in theaters heard the same audio that sound engineers heard in the listening booth after the final audio mix. Eventually, that goal has mutated.
The new THX idea was to ensure that home theater buffs heard the same quality and levels of audio as those sound engineers. Most people now about THX through logos on certified hardware. The implication of buying THX certified gear is that you get that sound mixing room environment. Any home theater enthusiast will know this simply isn’t the case. Simply buying THX certified equipment does not guarantee good sound, there are many other much much more important things that need to be right than the certification on equipment (for example room acoustics). THX certification brings to the table hardware that meets a consistent, minimum set of standards. To get good sound you need to use them in the right way and have good room acoustics.
According to AnandTech article THX Certified HDTVs – Useful or Just Marketing? the THX goal has mutated again. The article tells how the THX certification business works and what it means for TVs. THX tries to define a listening (or, in the case of HDTVs, viewing) experience, rather than just a set of hardware specs. The very act of doing that makes the company somewhat controversial. Since the logo program is a major part of THX’s revenue stream, obvious potential conflicts can occur. What does it mean when THX certifies an HDTV and does it matter anyway? What does the THX mode in an certified HDTV do? Read the article and make your own conclusions. The implications of a THX logo are perhaps stronger than the actual end result.