When you are watching a movie with the playback volume set to “0” on a THX Certified Receiver, you experience every sound element exactly like it was produced by the filmmaker—with the same fidelity, detail and clarity.

What is Reference Level?

Manufacturing receivers and speakers that can achieve THX Reference Level is no simple task. It requires a tremendous amount of power to drive an audio system effortlessly without clipping or distorting. To ensure the audio products can reach this peak performance, THX developed a set of standards as part of its THX Ultra2, THX Select2 and I/S Plus certifications.

• Experience Studio Clarity: THX Certified Receivers reproduce studio Reference Level, 85dB SPL with 20dB of headroom.
• Reference Level for your Room: THX Ultra2 Plus, THX Select2 Plus and THX I/S Plus certification categories deliver Reference Level performance in your specific room size.
• Distortion-free Playback: THX Certified Receivers and speakers are designed to recreate Reference Level with minimal distortion.

Listening Below Zero

Of course, there is a downside to watching all of your films at Reference Level—it is often too loud for your neighbors. But, when you lower the volume level, bass sounds, surround effects and other sound elements can be lost or perceived differently. To correct this, THX developed a technology called THX Loudness Plus, which lets you experience the rich details of a movie or game soundtrack without driving your neighbors crazy.

Re-EQ

Many movie soundtracks are mixed in studios for playback in large cinema auditoriums with an array of speakers. When played on home systems, they may appear abrasive and edgy. Re-EQ establishes a more accurate tonal balance when enjoying movies in your home.

Other THX Receiver Technologies

THX Certified Receivers also feature THX Adaptive Speaker Array technology, which establishes surround sound modes for movies, music and games, and THX Loudness Plus for enjoying surround soundtracks at lower volume levels.

What is THX ASA?

Today, movie, music and games are created in different types of studio environments, with multiple speaker configurations. The dilemma? Finding a single listening solution for playing different types of media, without physically moving your speakers. THX ASA addresses this by providing the following Listening Modes:

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.

Click here to learn more about THX Certified Receiver features.

What is THX Loudness Plus?

All movies, music and games are mixed at Reference Level in the studio, to be played back at the same Reference Level in the cinema or home theater (0 db on the volume dial for THX Certified Receivers is equal to the studio Reference Level). However, many of us find Reference Level is too loud for our homes. But, turning the volume down often means that elements of movie, music and other soundtracks are lost or perceived differently from the original sound mix.

THX Loudness Plus maintains the integrity of soundtracks when listening below Reference Level. The technology compensates for the tonal and spatial shifts that occur when the volume level is reduced. By automatically raising the levels of the ambient sound, you experience the true impact of movies, music and games regardless of the volume setting.

How Does THX Loudness Plus work?

THX Loudness Plus incorporates two new THX Technologies. As the user changes the volume, THX Multi-channel Spectral Balancing™ and THX Dynamic Ambience Preservation™ automatically and seamlessly apply the appropriate compensation. This delivers a more accurate listening experience at any volume level.

THX Multi-channel Spectral Balancing™

adjusts frequency response to counter the perceptual loss of low and high frequency sound in all channels. Begins with a flat response at Reference Level, and continually adjusts the response as the user selects lower listening levels. The equalization is applied to all channels in a multi-channel listening environment.

THX Dynamic Ambience Preservation™

Surround channel processing preserves the spatial detail that is lost when listening below Reference Level. It automatically shapes the output on surround channels to maintain the perceived balance in the original mix.

THX Loudness Plus automatically adjusts the front-to-back speaker level relationship as you turn the volume level down.