See Also: THX Certification
, THX Sound System
for alike nodes.
To clear something up right off the bat, THX is also an OnlineSpeak
abbrevation of "Thank You." (1)
(Thanks, Thanx, Thnx, Thx) But that isn't what this node is about. :)
The Name Itself:
The "THX" abbreviation has been dubbed Th
tensions on numerous occasions, though this is incorrect. (2)
The name derives from George Lucas' first film, THX-1138
. Beyond that, it's not known to stand for much of anything.
THX was designed in the early 1980's by George Lucas
. His mission: To find a way to be certain that films would look and sound exactly the same at every theatre around the world. 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
A common misconception is that THX certification applies only to the audio aspects of films; THX certification by nature specifies a certain picture quality, as well.
A THX certification
means that a theatre has addressed and dealt with the following problems with the showing of movies:
- Outside noise
- Inside noise
- Audio distortion
- Obstructed or uncomfortable viewing angles
- Reverberation in the auditorium
- Insufficiently bright images
- Unequalized or poor audio
In addition, they have (a)
Paid for expensive, THX-built equipment, and/or (b)
Paid for a THX-team to tour and inspect the facilities. This is usually a very expensive process, and as such, many THX-quality locations and devices do not, in fact, have certifications.
: When watching a movie with a standard 2.35:1 aspect ratio
, people sitting in the end seats on the back row must have a viewing angle of at least 26 degrees (36 degrees is considered optimal). No seat can have a partially obstructed view. Additionally, the movie's sound must be clear and distinct from any seat.Echo:
You should not hear any echo anywhere in a THX certified theatre.Projector:
The projector must be aimed within 5% of the center of the screen.Noise:
The amount of outside noise should not exceed NC-30 per octive, which is comparable to the outside noise you'd hear from inside a church.
Sound Details: (the following was taken almost directly from a website, see below)
In developing the criteria for THX sound, THX engineers looked at two distinct parts of a sound system:
THX At Home:
The A-chain comprises the components that decode the sound from whatever format it is in and process that signal to remove noise. This includes the audio pickup on the projector and the cinema sound processor. Digital sound formats, such as DTS, Dolby Digital and SDDS, and noise reduction systems, such as Dolby A and Dolby SR, are systems that improve the A-chain.
Basically, the B-chain is the rest of the sound system (THX crossover, power amplifiers and speakers). The THX engineers realized that no matter how good the sound coming out of the cinema processor was, a weak B-chain sound system could ruin it. To prevent this problem, THX patented a sound system design consisting of a special crossover and components from a list of THX-approved equipment. The engineers at THX subject all of the professional audio equipment on the list to a battery of tests to ensure that it meets the specifications they have established.
Anything at home that has a THX logo has been through a Digital Mastering Program
. This is a professional services group that works with studios and post production facilities to ensure the highest standards are applied for sound, video, compression, and replication. Note that unless you have THX certified theatre equipment setup in your house, you won't come near the majesty
of all that is THX.
Useless Facts about THX:
/msg me if you have any info to add, 'specially useless facts. I'll be happy to alter.
Sources Cited: (1) User: 65535 (2) User: Codepie (3) The "How Stuff Works" Website was almost ripped directly ;)