T+A Elektroakustik DD 1535 R manual Surroundsoundexplanatorynotes, Generalinformation

Surroundsoundexplanatorynotes

Generalinformation:

The following section is not concerned directly with the operation of your DD1535R decoder, but is rather intended to explain some of the terms which arise in connection with surround systems. It is intended to help you understand and exploit the facilities and capabilities of your DD1535R to the full.

As we all know, a normal stereo recording has two channels - left and right. When stereo material is reproduced in your listening room, the entire sound event takes place on an imaginary stage which covers the space between the two loudspeakers.

The listener is able to locate specific sound events over the width of the stage; with good recordings there is also a slight impression of depth, i. e. behind the speakers. Nevertheless, normal stereophonic reproduction always leaves the listener isolated from the event.

As a result it is impossible to recreate the excitement of a live atmosphere, as in a real concert hall, since the acoustics of the concert hall are crucially influenced by sound reflections from the side and back walls, the floor, the ceiling, and from objects inside the hall.

The reflected sound comes from any number of directions - not just from the front. If a sound event is to be reproduced with real fidelity, it therefore follows that a proportion of the sound must emanate from all directions in the room, that the “reflections” must be timed accurately, and that they must be generated at a realistic level.

Reproducing television sound via a conventional stereo system is problematic, because it is often impossible to locate dialogue on the screen itself.

A further point is that exotic sound effects have been in use in the cinema since the 1950’s, using proper multi- channel sound systems. These effects are often crucial to the overall impact of a film, but they cannot be reproduced at home with a conventional stereo sound system.

Over the last few years surround technologies have been developed which make it possible to experience all these effects within the listener’s own four walls, with the result that a far greater simulation of reality is possible than with conventional stereo.

For an effective surround system we always recommend the installation of a centre loudspeaker, which is installed below or directly above the TV set. This loudspeaker helps greatly in locating particular sound events (especially dialogue) on the TV screen itself.

Typesofreproduction

The DD1535R makes available a range of different types of reproduction: multichannel mode, mono/stereomode andsoundfields.

The surround receiver ‘remembers’ the setting for each input, and reverts to the mode of operation which was last used for that input when you switch to it from another input.

Multichannelmode(surround):

Mode of operation for the reproduction of multi-channel programmes (e. g. DOLBY Pro Logic II, DOLBY DIGITAL, dts, etc.)

Digital multi-channel signals are detected by the encoding methods employed, and the surround receiver automatically sets the correct loudspeaker assignment. The current reproduction mode is displayed on the front panel screen.

For analogue input signals the correct mode of operation cannot be detected automatically by the decoder. In this case the surround receiver always reverts to Dolby Pro Logic II decoding. If the signal is actually in a different form (stereo, mono - see below), then the mode must be set manually instead of surround mode.

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