Surround Mode Selection
One of the most important features of the AVR 1550 is its ability to reproduce a full multichannel surround sound field from digital sources, analog matrix surround encoded programs and standard stereo or even mono programs. In all, a total of eleven listening modes are available on the AVR 1550.
Selection of a surround mode is based on person- al taste, as well as the type of program source material being used. For example, motion pic- tures, CD’s or TV programs bearing the logo of one of the major surround encoding processes, such as Dolby Surround should be played in either the Dolby Pro Logic II Movie (with movies) or Music (with music) surround mode.
When no rear speakers are in use, the Dolby 3 Stereo mode should be selected with all surround recordings.
Note that when Dolby Digital 2.0 signals (e.g. "D.D. 2.0" tracks from DVD), that are encoded with Dolby Pro Logic information, are received via any digital input, the Dolby Pro Logic II Movie mode will be selected automatically (in addition to the Dolby Digital mode) and will decode a full range 5.1 channel surround sound even from those recordings (see also "Dolby Digital" on page 22).
To create wide, enveloping sound field environments and defined pans and flyovers with all analog stereo recordings select the Dolby Pro Logic II Music or Emulation mode.
NOTE: Once a program has been encoded with matrix surround information, it retains the sur- round information as long as the program is broadcast in stereo. Thus, movies with surround sound may be decoded via any of the analog surround modes such as Dolby Pro Logic II, when they are broadcast via conventional TV stations, cable, pay TV and satellite transmission. In addition, a growing number of made-for-tele- vision programs, sports broadcasts, radio dramas and music CDs are also recorded in surround sound. You may view a list of these programs at the Dolby Laboratories Web site at www.dolby.com.
Even when a program is not listed as carrying intentional surround information, you may find that the Dolby Pro Logic II, Dolby 3 Stereo modes often deliver enveloping surround presentations through the use of the natural surround information present in all stereo recordings.
However, for stereo programs without any surround information the Theater, Hall and 5CH Stereo modes should be tried (effective particu- larly with old ”extreme” stereo recordings) and for mono programs, we suggest that you try the Theater or Hall modes.
Surround modes are selected using either the front panel controls or the remote. To select a surround mode from the front panel, press the Surround Mode Selector 7to scroll through the list of available modes. To select a surround mode using the remote, press the Surround Mode Selector9, and then press the ⁄/ ¤ buttons Cto change the mode. As you press the buttons, the Surround mode name will appear in the Main Information Display M, and an individual mode indicator will also light up CDFHJ. Regard that any time a surround mode is changed it remains associated with the input just selected until another choice is made.
NOTE: The name of each Surround Mode will scroll through the Main Information Display
Mwhile the modes are being selected. To avoid exiting from the surround mode selection process, be certain to push the ⁄/ ¤ buttons Cwhile a mode name is still visible.
Note that the Dolby Digital or DTS modes may only be selected when a digital input is in use. In addition, when a digital source is present, the AVR 1550 will automatically select and switch to the correct mode (Dolby Digital or DTS), regard- less of the mode that has been previously select- ed. For more information on selecting digital sources, see the following section of this manual.
To listen to a program in traditional two channel stereo, using the front left and front right speak- ers only (plus the subwoofer if installed and con- figured), follow the instructions shown above for using the remote until SURR OFF appears in the Main Information Display M.
Digital Audio Playback
Digital audio is a major advancement over older analog matrix surround systems. It delivers five discrete channels: left front, center, right front, left surround and right surround. Each channel reproduces full frequency range (20Hz to 20kHz) and offers dramatically improved dynamic range and significant improvements to signal-to-noise ratios. In addition, digital systems have the capability to deliver an additional channel that is specifically devoted to low frequency informa- tion. This is the “.1” channel referred to when you see these systems descibed as “5.1”.
The bass channel is separate from the other channels, but since it is intentionally bandwidth limited, sound designers have given it that unique designation.
Dolby Digital
Dolby Digital (originally known as AC-3®) is a standard part of DVD, and is available on specially encoded LD discs and satellite broad- casts and it is a part of the new high-definition television (HDTV) system.
Note that an optional, external RF demodulator is required to use the AVR 1550 to listen to the Dolby Digital sound tracks available on laser discs. Connect the RF output of the LD player to the demodulator and then connect the digital output of the demodulator to the Optical or
Coaxial inputs of the AVR 1550.
No demodulator is required for use with DVD players or DTS-encoded laser discs.
DTS
DTS is another digital audio system that is capa- ble of delivering 5.1 audio. Although both DTS and Dolby Digital are digital, they use different methods of encoding the signals, and thus they require different decoding circuits to convert the digital signals back to analog.
DTS-encoded sound tracks are available on select DVD and LD discs, as well as on special audio-only DTS CDs. You may use any LD, DVD or CD player equipped with a digital output to play DTS-encoded special audio-only CDs with the AVR 1550, but DTS-LDs can be played on LD players and DTS-DVDs on DVD players only. All that is required is to connect the player’s output to either the Optical or Coaxial input on the
