Surround

The AVR-2805 is equipped with a digital signal processing circuit that lets you play program sources in the surround mode to achieve the same sense of presence as in a movie theater.

Dolby Surround

(1)Dolby Digital

Dolby Digital is the multi-channel digital signal format developed by Dolby Laboratories.

Dolby Digital consists of up to “5.1” channels - front left, front right, center, surround left, surround right, and an additional channel exclusively reserved for additional deep bass sound effects (the Low Frequency Effects – LFE – channel, also called the “.1” channel, containing bass frequencies of up to 120 Hz).

Unlike the analog Dolby Pro Logic format, Dolby Digital’s main channels can all contain full range sound information, from the lowest bass, up to the highest frequencies – 22 kHz. The signals within each channel are distinct from the others, allowing pinpoint sound imaging, and Dolby Digital offers tremendous dynamic range from the most powerful sound effects to the quietest, softest sounds, free from noise and distortion.

2Dolby Digital and Dolby Pro Logic

Comparison of home surround

Dolby Digital

Dolby Pro Logic

systems

 

 

 

 

 

No. recorded channels (elements)

5.1 ch

2 ch

 

 

 

No. playback channels

5.1 ch

4 ch

 

 

 

Playback channels (max.)

L, R, C, SL, SR, SW

L, R, C, S (SW - recommended)

 

 

 

Audio processing

Digital discrete processing

Analog matrix processing Dolby

Dolby Digital encoding/decoding

Surround

 

 

 

 

High frequency playback limit of

20 kHz

7 kHz

surround channel

 

 

 

 

 

2Dolby Digital compatible media and playback methods

Marks indicating Dolby Digital compatibility: .

The following are general examples. Also refer to the player’s operating instructions.

Media

Dolby Digital output jacks

Playback method (reference page)

 

 

 

LD (VDP)

Coaxial Dolby Digital RF output jack

Set the input mode to “AUTO”.

1

 

(Page 34)

 

 

 

 

 

DVD

Optical or coaxial digital output

Set the input mode to “AUTO”.

(same as for PCM)

2

(Page 34)

 

 

 

 

Others

Optical or coaxial digital output

Set the input mode to “AUTO”.

(satellite broadcasts, CATV, etc.)

(same as for PCM)

 

(Page 34)

 

 

 

 

1 Please use a commercially available adapter when connecting the Dolby Digital RF output jack of the LD player to the digital input jack.

Please refer to the instruction manual of the adapter when making connection.

2 Some DVD digital outputs have the function of switching the Dolby Digital signal output method between “bit stream” and “(convert to) PCM”. When playing in Dolby Digital surround on the AVR- 2805, switch the DVD player’s output mode to “bit stream”. In some cases players are equipped with both “bit stream + PCM” and “PCM only” digital outputs. In this case connect the “bit stream + PCM” jacks to the AVR-2805.

ENGLISH

(2)Dolby Pro Logic IIx

•Dolby Pro Logic IIx furthers the matrix decoding technology of Dolby Pro Logic II to decode audio signals recorded on two channels into up to 7.1 playback channels, including the surround back channel. Dolby Pro Logic IIx also allows 5.1-channel sources to be played in up to 7.1 channels.

The mode can be selected according to the source. The Music mode is best suited for playing music, the Cinema mode for playing movies, and the Game mode for playing games. The Game mode can only be used with 2-channel audio sources.

(3)Dolby Pro Logic II

•Dolby Pro Logic II is a new multi-channel playback format developed by Dolby Laboratories using feedback logic steering technology and offering improvements over conventional Dolby Pro Logic circuits.

•Dolby Pro Logic II can be used to decode not only sources recorded in Dolby Surround ( ) but also regular stereo sources into five channels (front left, front right, center, surround left and surround right) to achieve surround sound.

•Whereas with conventional Dolby Pro Logic the surround channel playback frequency band was limited, Dolby Pro Logic II offers a wider band range (20 Hz to 20 kHz or greater). In addition, the surround channels were monaural (the surround left and right channels were the same) with previous Dolby Pro Logic, but Dolby Pro Logic II they are played as stereo signals.

•Various parameters can be set according to the type of source and the contents, so it is possible to achieve optimum decoding (see page 41).

Sources recorded in Dolby Surround

These are sources in which three or more channels of surround have been recorded as two channels of signals using Dolby Surround encoding technology.

Dolby Surround is used for the sound tracks of movies recorded on DVDs, LDs and Video cassettes to be played on stereo VCRs, as well as for the stereo broadcast signals of FM radio, TV, satellite broadcasts and cable TV.

Decoding these signals with Dolby Pro Logic II makes it possible to achieve multi-channel surround playback. The signals can also be played on ordinary stereo equipment, in which case they provide normal stereo sound.

There are two types of DVD Dolby surround recording signals.

q2-channel PCM stereo signals w 2-channel Dolby Digital signals

When either of these signals is input to the AVR-2805, the surround mode is automatically set to Dolby Pro Logic II when the “DOLBY/DTS SURROUND” mode is selected.

2Sources recorded in Dolby Surround are indicated with the logo mark shown below. Dolby Surround support mark:

Manufactured under license from Dolby Laboratories.

“Dolby”, “Pro Logic” and the double-D symbol are trademarks of Dolby Laboratories.

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