B&K Reference 50 Owner's Manual page 9

Stereo - Stereo contains two discrete, front left and right full range audio channels. This is the most common
format for music and is also used on many movies. You may get stereo from any source - digital or analog. Sound
will normally come from the seven speaker channels, but your processor can produce stereo in one (mono) to
seven channels (see "Audio Modes under Operation").
Dolby Pro Logic - Dolby Pro Logic is a refinement of Dolby Surround, which was the earliest form of true
surround processing. Like Stereo, Dolby Surround contains two discrete, full range audio channels. In addition, a
monaural, limited range surround channel is encoded on the two stereo channels in a process called matrixing.
The surround channel information is encoded in positive polarity on the left channel and in negative polarity on the
right channel. The Dolby Processor can detect this encoding (left minus right) and send that information to the
surround channels. Dolby Pro Logic adds additional processing to produce a full range center channel by
extracting the mono information from the left and right channel. This is the most common format for all but the
most recent movies. Music sources are occasionally encoded in Dolby Surround. However, many people prefer to
use Pro Logic processing on all of their stereo sources. The center channel extraction process often yields
improved stereo imaging, especially when you are sitting away from the "sweet spot" at center of the listening
area. The surround channel processing often lends a pleasing ambiance even to material that is not encoded in
Dolby Surround. Dolby Pro Logic is fully compatible with stereo and you may get it from any source - digital or
analog. Sound will normally come from all seven speakers in your system, but your processor can produce sound
in one (mono) to seven channels (see "Audio Modes under Operation").
Dolby Pro Logic II - Pro Logic II brings exciting new features and advanced performance for decoding the many
thousands of existing Dolby Surround programs, making them sound more like a discrete Dolby Digital 5.1-
channel version than ever before. Pro Logic II is able to decode the thousands of existing Dolby Surround movies
and TV shows already on the shelf, compatibly, and with enhanced image stability. The improvements in
decoding techniques mean that the discreteness of the sound field elements are better preserved in the decoding
process than was possible with the now universally standard Pro Logic technology. Pro Logic II offers a music
mode to expand stereo non-matrix recordings into a five-channel layout in a way that does not diminish the
subtlety and integrity of the original stereo recordings.
Dolby Digital - Dolby Digital contains up to five discrete, full range audio channels plus an additional Low
Frequency Effects (LFE) channel. The LFE channel contains only low frequency information for enhanced sound
effects in movies. This combination of five discrete channels plus a LFE channel is often referred to as 5.1
channels. Dolby Digital is a digital format only. It must be delivered to your processor over a coaxial or optical
digital cable. As of the writing of this manual, Dolby Digital is commercially available on DVD and Satellite (Also
see Dolby Digital RF below). It is also possible to create your own Dolby Digital CDs and DATs if you have the
recording equipment. You can't directly record Dolby Digital onto mini disc or digital compact cassette since these
devices add their own compression, which is incompatible with the Dolby Digital compression. Not all Dolby
Digital recordings will include all five channels, and, in fact, it is common on DVDs to have two channel Dolby
Digital with or without Pro Logic processing. Sound will normally come from all seven speakers in your system,
but your processor can produce sound in one (mono) to seven channels (see "Audio Modes under Operation").
Dolby Digital RF - Dolby Digital RF is identical to normal Dolby Digital except that it uses a special RF encoding
scheme to put the bitstream on Laser discs without replacing the normal stereo (or Dolby Surround) PCM
bitstream that is normally available from laser disc. In order to use Dolby Digital RF laser discs you must have a
B&K DT-1 RF demodulator or similar product from another manufacturer. For best results with your processors
Plug and Play capability we recommend the B&K DT-1.
Dolby Digital Surround EX - Dolby Digital Surround EX is a new movie sound track that greatly enhances the
sense of spatial and positioning of the surround channel sound. This system was developed jointly by Lucasfilm
THX and Dolby Laboratories, using Lucas film's idea of improving spatial expression and achieving a 360-degree
sound positioning with Dolby Laboratories' matrix encoding technology. The surround back channel is matrix-
encoded and inserted into both Dolby Digital SL (surround left) and Dolby Digital SR (surround right) channels.
Upon playback, a high precision digital matrix decoder within the Dolby Digital decoder into SL, SR and SB
channels may decode the signals.
DTS (Digital Theater Systems) - DTS is similar to Dolby Digital in that it provides 5.1 discrete audio channels.
However, it uses more digital data to encode the information and may provide greater fidelity than Dolby Digital.
DTS is a digital format only. It must be delivered to your processor over a coaxial or optical digital cable. No RF
demodulator is required for DTS laser discs since the DTS bitstream replaces the normal PCM bitstream. Like
Dolby Digital, you can create your own DTS DATs or CDs but not mini disc or digital compact cassette. As with
Dolby Digital, sound will normally come from all seven speakers in your system, but your processor can produce
sound in one (mono) to seven channels (see "Audio Modes under Operation").
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