THX, the trademark of THX Ltd., is the ultimate set of standards for home theatre sound. It incorporates a series of patented electronic and loudspeaker specifications designed to bring the big theatre experience right into your home.

THX Certified Home Theatre products deliver cinema-quality picture and Hi-end sound to home environments. Through optimized audio-visual technology and speaker placement, you get a movie experience at home that's as faithful as possible to what the director intended.

Products certified by THX assure the best possible quality in music and sound reproduction.

THX Certification is the “seal of approval” for speaker quality. It is the absolute assurance that your loudspeakers will reproduce all music and film material in the way that the composer and film director respectively intended.

No, Dolby Digital soundtracks can provide anything from mono to full 5.1-channel surround sound. DVD discs can even carry multiple versions of the soundtrack that differ in the number of channels.

A disc might contain a 5.1-channel sound mix with the dialogue in one language, a Dolby Surround-encoded two-channel mix in another language, and a mono track with the directors’ comments or other supplementary information.

The default soundtrack will vary from disc to disc, so always check the DVD disc’s Language menu for the choices offered.

DTS (Digital Theater Systems) is the alternative to Dolby Digital when it comes to digital surround sound. Like Dolby Digital, DTS is a discrete digital multichannel audio format.DTS is most often associated with movie soundtracks, but this high-resolution approach to surround sound is also being used to create multichannel versions of music recordings, too.

Whether we're talking about a movie theater or a home theater, DTS, like Dolby Digital,is an encode/decode system: to play back a Dolby Digital soundtrack, you need a Dolby Digital decoder, and to play back a DTS soundtrack you need a DTS decoder.

Dolby® Digital technology is an advanced form of digital audio coding that makes it possible to store and transmit high-quality digital sound far more efficiently than was previously possible. First used in movie theaters in 1992, Dolby Digital technology is the result of decades spent by Dolby Laboratories developing signal-processing systems that exploit the characteristics of human hearing.

Dolby Digital programs can deliver surround sound with up to five discrete full-range channels: Left, Center, Right, Left Surround, Right Surround-plus a sixth channel for powerful low-frequency effects. As it needs only about one-tenth the bandwidth of the others, the LFE channel is referred to as a ".1" channel (and sometimes erroneously as the "subwoofer" channel).

The different types of DTS formats are:

• Standard 5.1 channel DTS Surround decoder

• DTS-ES (DTS Extended Surround) including two variants, DTS-ES Matrix and DTS-ES Discrete 6.1. The latter provides 6.1 discrete channels, with a discretely recorded (nonmatrixed) center-surround channel, while the first one provides 5.1 discrete channels, with a matrixed center-surround audio channel

• DTS Neo:6, like Dolby's Pro Logic IIx system, can take stereo content and convert the sound into 5.1 or 6.1 channel format

• DTS 96/24 allows the delivery of 5.1 channels of 24-bit, 96 kHz audio and high quality video on the DVD Video format. It can also be placed in the video zone on DVD Audio discs, making these discs playable on all DTS-compatible DVD players

• DTS-HD High Resolution Audio, along with DTS-HD Master Audio, comprise the DTS-HD extension to the original DTS audio format. It delivers up to 7.1 channels of sound at a 96 kHz sampling frequency and 24-bit depth resolution. DTS-HD High Resolution Audio is selected as an optional surround sound format for Blu-ray Disc and HD DVD, with constant bit rates up to 6.0 Mbit/s and 3.0 Mbit/s, respectively. It is supposed to be an alternative for DTS-HD Master Audio where disc space may not allow it

• DTS-HD Master Audio supports a virtually unlimited number of surround sound channels, can downmix to 5.1 and two-channel, and can deliver audio quality at bit rates extending from DTS Digital Surround up to lossless (24-bit, 192 kHz). DTS-HD Master Audio is selected as an optional surround sound format for Blu-ray and HD DVD, where it has been limited to a maximum of 8 discrete channels. DTS-HD MA supports variable bit rates up to 24.5 Mbit/s on a Blu-ray Disc and up to 18.0 Mbit/s for HD DVD, with two-channel encoded at up to 192 kHz or 8 channels encoded at 96 kHz/24 bit

The different Dolby Digital formats are:

	Dolby Digital is the common version containing up to six discrete channels of sound
	Dolby Pro Logic IIx technology lets you take your listening environment to the next level by expanding your two-channel (stereo) or 5.1-channel audio to 6.1- or 7.1-channel playback. Dolby Pro Logic IIx also extends Dolby Pro Logic's sophisticated technology for the smoothest surround sound experience possible.
	Dolby Pro Logic IIz takes surround to the next level by adding front height channels—an additional pair of speakers positioned above the front left and right speaker. What that means for you is a surround sound experience with incredible depth and dimension. Most surround sound solutions use digital signal processing (DSP) to artificially model listening environments. Expanding on proven Dolby Pro Logic IIx technology, Dolby Pro Logic IIz stands apart by identifying and decoding spatial cues that occur naturally in all content—stereo and 5.1 broadcast, music CDs, DVDs, 5.1- and 7.1-channel Blu-ray Discs, and video games. It then processes ambient sound and certain amorphous effects such as rain or wind and directs them to the front height speakers.
	Dolby Digital EX is similar in practice to Dolby's earlier Pro-Logic format, which utilized matrix technology to add a center channel and single rear surround channel to stereo soundtracks. EX adds an extension to the standard 5.1 channel Dolby Digital codec in the form of matrixed rear channels, creating 6.1 or 7.1 channel output
	Dolby TrueHD, developed by Dolby Laboratories, is an advanced lossless audio codec based on Meridian Lossless Packing. Support for the codec was mandatory for HD DVD and is optional for Blu-ray Disc hardware. TrueHD supports 24-bit, 96 kHz audio channels at up to 18 Mbit/s over 14 channels (HD DVD and Blu-ray Disc standards currently limit the maximum number of audio channels to eight). It also supports extensive metadata, including dialog normalization and Dynamic Range Control
	Dolby Digital Plus gives you access to more content and lets you experience all of the enveloping surround sound that Blu-ray Disc™, high-definition (HD) broadcast, and streamed and downloaded media make possible. Enables up to 7.1 channels of theatre-quality sound, unlocking the full audio potential from Blu-ray Discs, HD broadcast, and streamed and downloaded media.

Of course. Not only they are suitable for High Definition audio formats however, but they are indispensable to get the best out of them. These High Definition audio formats simply deliver discreet uncompressed audio, coded using extremely high bit rates, for all the channels of a modern multichannel system. The result is that you can hear (if your system permits it!) all the details that the director and musicians wanted to breath into their creation. These details and depth are perfectly rendered by the Crystal Audio speakers.

Bottom line: The new HD audio formats are useless if your speakers are not so good as to reveal their depth!

The new High Definition audio formats use extremely high bit rates to transmit the massive amount of data needed to decode the information for all channels of a multichannel system. Thus, conventional connections like the SPDIF/Toslink are rendered pretty useless. Thanks to the HDMI however (note, it must be version 1.3) the connection of HD sources to your A/V receiver is as easy as plugging one cable. Alternatively you can transfer the signal in the analog field, using one, high quality, audio interconnect per channel. The use of a quality HDMI, version 1.3, is highly proposed though.