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Introduction – general use
The SDDS sound format
SDDS (Sony Dynamic Digital Sound) is designed to
reproduce up to 8 channels of high quality audio in
cinema theatres.
The audio data is stored on the film strip, on both outer
edges, outside the perforation holes. The SDDS track is
printed in the cyan colour layer of the film, and will
appear as small pixels in a blueish or greenish colour.
The two tracks are called the P-track and S-tracks,
indicating which is closest two the picture and which is
closest to the conventional analogue sound track.
A unique SDDS back-up feature makes it possible for the
system to play with one track only over short periods
without any audible artefacts.
The DFP-2000 System
The DFP-D2000 has been designed to play back SDDS digital sound tracks in cinemas already
equipped with cinema processors for playback of other sound formats.
As the last sound processor in the audio chain prior to the power amplifiers and/or crossover
networks, the DFP-2000 decoder acts like a gate that keeps the signal flow from the central
cinema processor open as long as no SDDS data is detected.
The moment SDDS data is decoded, this gate for the central cinema processor (referred to as
"bypass inputs") is closed. Instead the gate for the SDDS audio is opened so that the SDDS
audio is routed to the power amplifiers and speakers.
As soon as the SDDS data stream stops, the DFP-2000 will switch back to the bypass inputs.
This state is referred to as "soft bypass" to distinguish it from the state, where the operator
actively presses the bypass button on the front panel, forcing the DFP-2000 to "hard bypass".
In this hard bypass mode, the SDDS decoder will not resume SDDS playback unless the
bypass button is pressed again. The same can be accomplished by switching off the mains
power of the DFP-2000.
The playback mode (SDDS or soft bypass) can be checked by monitoring the Data present
indicator on the front panel.
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