The Re-Equalization circuit found in THX processors, corrects the over-bright sound of movie soundtracks. Movies are mixed in cinemas with a controlled high frequency roll-off, called the "X-Curve". This curve, an international standard, is part of every mixing and cinema's playback system because high frequency roll-off is appropriate for sound sources that are not close. But since home listening distances are shorter, audio mixed under the "X-Curve" sounds too bright when played back through flat response speakers. To match sound for smaller spaces and distances, THX uses a special Re-Equalization Curve, designed for home environments, to restore the correct tonal balance of a movie soundtrack.

* Image explaining this THX technology belongs to THX Ltd

Adaptive Decorrelation compensates for monophonic surround channels in Dolby Pro Logic. In the cinema, this goes unnoticed since the sound is mixed up by the large number of surround speakers and by small room reflections. Your left ear and right ear never get identical sounds, so you never identify the surround sounds as mono. (Even with Dolby Digital and DTS sound and "split" left/right surround channels, mixers use a lot of mono surround sound effects.)

In a home environment, you’d detect the mono "feel" of the surround channels. In response, the THX Decorrelation Circuit subtly adjusts the time and phase of one surround channel against the other. This constantly changing time and phase differences means that your left ear and right ear never hear identical signals. The sound is never identified as mono and remains spacious, just like in the cinema. For Dolby Digital and DTS split surround signals, an intelligent Adaptive De-correlation circuit de-correlates the surround channels only when it senses mono surround signals.

* Image explaining this THX technology belongs to THX Ltd

THX Loudness Plus is a new volume control technology with which home cinema audiences can now experience the rich details and ambient sound in a surround mix at any volume level. THX Loudness Plus incorporates two new THX technologies. As you change the volume, THX Multi-channel Spectral Balancingâ„¢ and THX Dynamic Ambience Preservationâ„¢ automatically and seamlessly apply the appropriate compensation. This delivers a more accurate listening experience at any volume level.

Basically, what it does is to automatically adjust the front-to-back speaker level relationship as you turn the volume level down so that the perceived sounds match as closely as possible the original mix as played back at the reference level (as was recorded and mixed in the studio).

THX Advanced Speaker Array (ASA) recreates the 5.1 studio surround sound field in your home by digitally reconfiguring the surround channels for the type of media you are enjoying. Featured on all Certified Receivers, THX ASA establishes THX Listening Modes, making it convenient to have one speaker set up for movies, music and games. 

	THX Cinema Mode Recreates the ambiance of the movie theater by positioning the 5.1 mix to immerse you in the movie’s soundtrack.
	THX Games Mode Distributes the sound effects and dialogue generated by the game engine, placing the audio from a 5.1 mix source to the appropriate “action” location – creating 360-degree gaming experience.
	THX Music Mode Emulates the original studio environment by repositioning the 5.1 surround sound mix further behind you for an accurate and increased sense of spaciousness and localization – placing you directly in the recording session.

THX Surround EX

Decodes the third surround channel from the traditional two surround channels, creating a more immersive entertainment experience. 

* Images explaining these THX technologies belong to THX Ltd