Rotel RSP-1066 Overview of Surround Formats, Dolby Surround Dolby Pro Logic, Dolby Digital

RSP-1066Surround Sound Processor 14

Overview of Surround Formats

To get best performance from your RSP-1066, it helps to understand the many surround sound formats available today, to know which de- coding process to use for a particular record- ing, and how to select it. This section provides basic background information about surround sound formats. The next sections provide de- tailed operating instructions.

Dolby Surround

Dolby Pro Logic

The most widely available surround sound format for consumer audio/video is Dolby Surround®, available on nearly all commer- cial VHS tapes, many television broadcasts, and most DVDs. Dolby Surround is the con- sumer version of the analog Dolby Stereo system first introduced in the film industry in 1972. It is a matrix-encoding system that records front left, front center, front right, and a mono sur- round channel into a 2-channel stereo record- ing. During playback, a Dolby Pro Logic® de- coder extracts each channel and distributes it to the appropriate speakers.

Dolby Pro Logic decoding delivers a mono sig- nal with reduced high-frequency content to the surround speakers. The more advanced de- coder in the RSP-1066, Dolby Pro Logic II, in- creases the separation and frequency response of the surround channels for significantly im- proved performance with Dolby Surround en- coded recordings.

Dolby Pro Logic II decoding is used for any analog soundtrack or recording labeled “Dolby Surround” or any Dolby Digital 2.0 soundtrack. While it is specifically designed to decode Dolby Surround recordings, Dolby Pro Logic can derive surround sound from conventional 2-channel stereo recordings, using phase re- lationships to extract front, right, center, and surround channels.

Activate Dolby Pro Logic II decoding with the Dolby PLII/3ST button described in the next section of the manual.

Dolby Digital

In 1992, an entirely new digital recording system, called Dolby Digital, was first used in the film industry. Dolby Digital is a recording/ playback system that uses compression tech- niques to store large amounts of audio data efficiently, much like the JPEG format stores large photographs in small files on a computer. Dolby Digital is the standard audio format for DVDs and for digital television broadcasting in the United States.

The Dolby Digital system can be used to record up to six discrete audio channels, but can con be used for fewer. For example, a Dolby Digital

2.0recording is a 2-channel stereo record- ing such as a matrix encoded Dolby Surround soundtrack. To play this type of recording, use Dolby Pro Logic II decoding as previously de- scribed.

The most common use of Dolby Digital, in both the film industry and in home theater, is Dolby Digital 5.1. Instead of encoding multiple sur- round channels on a two-channel recording, Dolby Digital 5.1 records six discrete chan- nels: front left, front center, front right, surround left, surround right, and a Low Frequency Ef- fects (LFE) channel containing ultra-low bass signals intended for a subwoofer. A Dolby Digi- tal decoder extracts the channels from the digital bitstream, converts them to analog signals and routes them to the appropriate speakers. All channels provide full frequency response with total separation between all channels and large dynamic range capability. A Dolby Digital 5.1 soundtrack will provide significantly more impressive surround sound than Dolby Pro Logic decoding of matrix Dolby Surround.

Decoding of Dolby Digital 5.1 soundtracks is automatic. When the RSP-1066 detects a Dolby

5.1signal on one of its digital inputs, it acti- vates the proper processing. Keep in mind that Dolby Digital is only available from digital sources (a DVD, a LaserDisc, or a Digital TV/ Cable/SAT tuner). Also, you must connect the source with a digital cable (coax or optical) to an active digital input on the RSP-1066.

NOTE: Many DVDs have a Dolby Digital 2.0 matrix soundtrack as the default, which should be decoded with Pro Logic II. The Dolby Digi- tal 5.1 soundtrack may have to be selected as an option from the setup menus at the be- ginning of the DVD. Look for a Dolby Digital

5.1selection under “Audio” or “Languages” or “Setup Options” when you insert the disc.

DTS 5.1

DTS® (Digital Theater Systems) is an alterna- tive digital format competing with Dolby Digital in both movie theaters and home theater markets. The basic features and functions of the DTS system are similar to those of Dolby Digital (for example, 5.1 discrete channels), however the technical details of the compres- sion and decoding processes differ somewhat and a DTS decoder is required.

Like Dolby Digital, DTS can only be used on a digital recording and, therefore, is only available for home use on LaserDiscs, DVDs, or other digital formats. To use the RSP-1066’s DTS decoder, you must connect your DVD player to the RSP-1066’s digital inputs.

As with Dolby Digital 5.1, detection and proper decoding of DTS 5.1 signals is automatic.

NOTE: DVDs with a DTS soundtrack almost always have it configured as an option to the standard matrix Dolby Surround format. To use DTS, you may have to go to the setup menus at the beginning of the DVD and se- lect “DTS 5.1” instead of “Dolby Surround” or “Dolby Digital 5.1”. In addition, many DVD players have the DTS digital bitstream turned off by default and cannot output a DTS soundtrack, even if selected on the disc’s menu, until you activate the player’s DTS out- put. If you here no sound the first time you attempt to play a DTS disc, you may have to go to the DVD player’s configuration menus and turn on the DTS bitstream. This is a one- time setting and need only be done once. See your DVD owners manual for details.

The RSP-1066 features a second type of DTS surround sound decoding: DTS Neo:6. This decoding system is similar to Dolby Pro Logic

IIin that it is designed for playback of any 2- channel stereo recording, either matrix-encoded or not. The Neo:6 decoder can by used with any conventional 2-channel source such a stereo TV or FM broadcast or a CD. It can also be used as an alternative method of decod- ing matrix-encoded Dolby Surround record- ings or TV broadcasts. Activate the DTS Neo:6 decoding with the DTS:Neo 6 button as de- tailed later in this section. DTS Neo:6 is not used with DTS 5.1 digital sources and the button need not be pressed for those recordings.