Rotel RSX-1055 owner manual and 7.1 Surround, Other Formats, DSP Digital Signal Processing

RSX-1055Surround Sound Receiver		16
DTS 5.1	6.1 and 7.1 Surround

matrix-encoded surround signals (such as non- flagged DTS-ES and Dolby Surround EX discs)

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 RSX-1055’s DTS decoder, you must connect your DVD player to the RSX-1055’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 hear 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 RSX-1055 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.

In 1999, the first Dolby Digital soundtrack was released to theaters with an additional cen- ter back surround channel, intended to increase the directional effects from behind the audi- ence. This additional surround channel is en- coded into the two existing surround channels in Dolby Digital 5.1, using a matrix encod- ing process similar to that used previously in Dolby Surround. This new extended surround capability is called Dolby Digital Surround EX.

DTS has added a similar capability for record- ing this extended surround information called DTS-ES®6.1 Matrix. They have also taken it one step further and developed the capabil- ity to record this extended surround informa- tion as a fully discrete channel in a system called DTS-ES®6.1 Discrete.

All of these systems are extensions of the ex- isting Dolby Digital 5.1 and DTS 5.1 digital surround sound formats. Users with one cen- ter back speaker (a 6.1 configuration) or two center back speakers (a 7.1 configuration) can take advantage of this extended surround in- formation. Users with traditional 5.1 channel systems can play Dolby Digital Surround EX or DTS-ES 6.1 discs and they will sound ex- actly the same as 5.1 channel discs in each respective format. The extended surround recordings are 100% backwards compatible.

If you have configured your system with one or two center back speakers, decoding of DTS-ES discs is automatic, just as it is with stan- dard DTS soundtracks. Likewise, decoding of Dolby Digital Surround EX discs is automatic with one exception. Some early Surround EX titles did not have the detection “flag” encoded on the disc. To activate the Dolby Digital Sur- round EX features for these discs or for stan- dard 5.1 channel Dolby Digital discs, use the Dolby PLII/3ST button described in the next section of this manual.

The RSX-1055 also features Rotel XS (eXtended Surround) processing that automatically ensures optimum extended surround performance on

6.1and 7.1 channel systems. The key ben- efit of Rotel XS is that it works at all times with all multichannel digital signals, even those that might not otherwise activate proper surround decoding for the center back channel(s). Al- ways active in any system configured with cen- ter back speaker(s), Rotel XS monitors the sur- round channels, properly decodes them, and distributes the extended surround channels to the center back speaker(s). Rotel XS works with

as well as non-matrix digital source material (such as DTS 5.1, Dolby Digital 5.1, and even Dolby Pro Logic II decoded Dolby Digital 2.0 recordings) to derive superb center back chan- nel surround effects.

Other Formats

Three other digital formats are not surround sound formats at all, but rather systems for digital 2-channel recordings.

The first is PCM 2-channel. This is a straight 2-channel digital signal such as that used for standard CD recordings.

The second is HDCD® encoding for compact discs. This system uses a variety of enhance- ments to improve the sonic performance com- pared to standard audio CDs. These discs, labeled HDCD, can be played on standard CD players. However, when the digital sig- nal is decoded using an HDCD decoder like that in the RSX-1055, they will provide excep- tional musical reproduction.

The RSX-1055 also features a decoder for the digital MP3 (MPEG1- Audio Layer 3) compres- sion format. MP3 format recordings are avail- able on the Internet and can be played on por- table MP3 players or some disc players that can read CD-ROM discs.

PCM 2-channel, HDCD, and MP3 are digital formats. They can only be decoded by the RSX-1055 from digital sources connected to the digital inputs.

DSP (Digital Signal Processing)

Finally, one more related issue to be addressed is DSP modes. Unlike all of the formats men- tioned above, DSP is not a recording/play- back system. Instead, it is a digital process- ing feature of the RSX-1055 that adds special acoustic effects to any signal. DSP process- ing can be used with Dolby Surround record- ings, Dolby Digital recordings, CDs, radio broadcasts, or any other source material; however, typically DSP settings would be used with source material for which there is no specific surround decoder.

In general, DSP is used to create the ambience of a large listening environment: a jazz club, a concert hall, a stadium, etc. It uses digital processing to delay the signal to various speak- ers and mix in various levels of reverberation. Its use is strictly a matter of personal taste.