Wow I never knew that THX was not a format at all

Sorry for the long post...but i am such a doofus i didn't know this. The common assumption is that THX is simply another movie sound format, but it turns out THX is not a sound format at all but something else entirely. THX, named after "THX 1138" (George Lucas' first feature film), was developed at Lucasfilm in the early 1980s. George Lucas wanted a way to ensure a movie would look and sound exactly the same no matter where it was played. Tomlinson Holman, former corporate technical director for Lucasfilm, and a team of THX engineers took on the challenge of developing a baseline set of standards.

They noted several theater shortcomings that might negatively affect an audience's enjoyment of a film:

Outside noise (from the lobby or other auditoriums)
Inside noise (from the projector or air conditioning)
Audio distortion
Obstructed or uncomfortable viewing angles
Reverberation in the auditorium
Insufficiently bright images
Unequalized or poor audio
The essence of THX is a set of guidelines that resolve these problems. To display the THX logo, a theater must adopt this set of standards and then be certified by Lucasfilm's THX division. The first movie to be shown in a THX-certified auditorium was "Return of the Jedi" in 1983. There are now more than 2,000 auditoriums around the world that have been certified.
Before a theater can be certified, a number of things must happen:

Licensing & Evaluation
Certification
Design
Approval
Construction/renovation
The first step in the process is for the theater owner and THX to take care of the licensing agreement. The theater owner agrees to lease the THX crossover equipment and pay for the right to use the THX logo. Once the theater owner signs the agreement, THX reviews either the architectural plan of the auditorium or, in the case of existing auditoriums, a survey of the current conditions.

The theater owner and a THX team then develop a design for implementing the infrastructure needed to meet THX specifications. After the theater owner has incorporated the design changes, THX will assist him or her in selecting equipment from the THX equipment list. The final design and equipment list is submitted to THX for approval. Once THX approves the list, the owner can begin actual construction or renovation.