T+A K 6 CV User Manual

T+A K 6 CV User Manual Manual pdf 9 page image

9 OperationSurround sound - explanatory notesGeneral informationThe following section is not concerned directly with theoperation of your K6, but is rather intended to explainsome of the terms which arise in connection with sur-round systems. It is intended to help you understand andexploit the facilities and capabilities of your K6 to the full.As we all know, a normal stereo recording has two chan-nels - left and right. When stereo material is reproducedin your listening room, the entire sound event takes placeon an imaginary stage which covers the space betweenthe two loudspeakers.The listener is able to locate specific sound events overthe width of the stage; with good recordings there is alsoa slight impression of depth, i.e. behind the speakers.Nevertheless, normal stereophonic reproduction alwaysleaves the listener isolated from the event.As a result it is impossible to recreate the excitement of alive atmosphere, as in a real concert hall, since theacoustics of the concert hall are crucially influenced bysound 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 direc-tions - not just from the front. If a sound event is to bereproduced with real fidelity, it therefore follows that aproportion of the sound must emanate from all directionsin the room, that the 'reflections' must be timed accu-rately, and that they must be generated at a realisticlevel.Reproducing television sound via a conventional stereosystem is problematic, because it is often impossible tolocate dialogue on the screen itself.A further point is that exotic sound effects have been inuse in the cinema since the 1950's, using proper multi-channel sound systems. These effects are often crucialto the overall impact of a film, but they cannot be repro-duced at home with a conventional stereo sound system.Over the last few years surround technologies have beendeveloped which make it possible to experience all theseeffects within the listener's own four walls, with the resultthat a far greater simulation of reality is possible thanwith conventional stereo.For an effective surround system we always recommendthe installation of a center loudspeaker, which is installedbelow or directly above the TV set. This loudspeakerhelps greatly in locating particular sound events (espe-cially dialogue) on the TV screen itself.Types of reproductionThe K6 makes available a range of different types ofreproduction: multi-channel mode, mono/stereo modeand sound fields.The K6 'remembers' the setting for each input, and re-verts to the mode of operation which was last used whenyou switch from one input to another.For the internal disc player the settings for CD and DVDare stored independently.Multi-channel mode (surround)Mode of operation for the reproduction of multi-channelprogrammes (e.g. DOLBY Pro Logic, DOLBY DIGITAL,dts, etc.).A digital multi-channel signal is detected by its encodingmethod, and the K6 automatically sets the correct loud-speaker assignment. The current reproduction mode isdisplayed on the front panel screen.For analogue input signals the correct mode of opera-tion cannot be detected automatically by the decoder.In this case the decoder always reverts to Dolby ProLogic decoding. If the signal is actually in a different form(stereo, mono - see below), then the mode must be setmanually instead of surround mode.Dolby Pro Logic II SurroundIn this process several independent signal channels arerecorded using two channels and a special encodingprocess. Since this process only requires two recordingchannels, it is compatible with many picture / soundsystems which are already widely in use (CD, videorecorder, TV etc.).The information is decoded at playback time and repro-duced in the listening room via four (left, right, 2 x sur-round) loudspeakers, although five speakers (with anadditional front center speaker) are preferable. DolbySurround encoded material is currently available mainlyin the film and video arena, recorded on video cassettesand DVDs, but many television programmes are nowbeing produced and transmitted using Dolby Surround.Dolby DigitalDolby Digital is a digitalmulti-channel surroundsystem which wasdeveloped specifically forspatial sound reproductionin connection with cinemafilms. The process utilisesfive separate soundchannels: three frontchannels (left, center,right) and two surroundchannels. A sixthindependent bass effectchannel is also present,catering for low frequency effects (LFE). That is whysuch systems are said to offer 5.1 channels.In comparison with Dolby Pro Logic, Dolby Digital pro-vides two independent surround channels which providegenuine spatial stereo sound, offering the same realisticstereo reproduction as provided by the front channels.The integral Dolby Digital decoder provides the means ofobtaining a genuine digital Dolby stereo cinema presen-tation in your own living room. The discrete digital re-cording process and the five playback channels guaran-tee a very wide dynamic range and accurate spatialorientation.The dynamic range is the difference in volume betweenthe quietest and loudest passages of a recording. Theoriginal soundtrack of a film generally features an ex-tremely wide dynamic range which the K6 can reproducein full.