JVC TH-A55 manual Creating realistic sound fields, Dolby Surround, DTS Digital Surround, DSP modes

Creating realistic sound fields

You can use the following surround modes to reproduce a realistic sound field.

•Dolby Surround

•Dolby Pro Logic II

•Dolby Digital

•DTS Digital Surround

•DSP modes

•DAP modes

•All Channel Stereo

7Dolby Surround

Dolby Pro Logic II*

Dolby Pro Logic II has a newly developed multichannel playback format to decode all 2 channel sources — stereo source and Dolby Surround encoded source — into a 5.1 channel.

The matrix-based encoding/decoding method used by Dolby Pro Logic II makes no limitation for the cutoff frequency of the treble from surround channel and enables stereo surround sound compared to conventional Dolby Pro Logic.

Dolby Pro Logic II enables to reproduce spacious sound from original sound without adding any new sounds and tonal coloration. Dolby Pro Logic II has two modes — Movie mode and Music mode:

•Pro Logic II Movie (PL II MOVIE)

Suitable for reproduction of Dolby Surround encoded sources

bearing the mark . You can enjoy soundfield very close to the one created with discrete 5.1 channel sounds.

•Pro Logic II Music (PL II MUSIC)

Suitable for reproduction of any 2 channel stereo music sources. You can enjoy wide and deep sound by using this mode.

•When Dolby Pro Logic II is activated, the GPLII indicator lights on the display window.

Dolby Digital*

Used to reproduce multichannel soundtracks of the software

encoded with Dolby Digital ().

Dolby Digital 5.1 ch (DOLBY D) encoding method (so-called discrete multichannel digital audio format) records and digitally compresses the front left channel, front right channel, center channel, surround left channel, surround right channel and LFE channel signals.

Since each channel is completely independent from the other channel signals to avoid interference, you can obtain much better sound quality with much stereo and surround effects.

NOTE

•Dolby Digital software can be roughly grouped into two categories- multichannel (up to “5.1” channel) and 2 channel software. To enjoy surround sounds while playing Dolby Digital 2 ch software, you can use Dolby Pro Logic II.

7DTS Digital Surround**

Used to reproduce multichannel soundtracks of the software encoded with DTS Digital Surround ( ).

DTS Digital Surround (DTS) is another discrete multichannel digital audio format available on CD, LD and DVD software. Compared to Dolby Digital, audio compression ratio is relatively low. This fact allows DTS Digital Surround format to add breadth and depth to the reproduced sounds. As a result, DTS Digital Surround features natural, solid and clear sound.

7DSP modes

DAP (Digital Acoustic Processor) modes

DAP modes have been designed to create important acoustic surround elements.

The sound heard in a live club, dance club, hall or pavilion consists of direct sound and indirect sound — early reflections and reflections from behind. Direct sounds reach the listener directly without any reflection. On the other hand, indirect sounds are delayed by the distances of the ceiling and walls (see the diagram below).

These indirect sounds are important elements of the acoustic surround effects. The DAP mode can reproduce a realistic sound field by adding these indirect sounds.

The following DAP modes are provided with this system.

LIVE CLUB	Gives the feeling of a live music club with a
	low ceiling.
DANCE CLUB	Gives a throbbing bass beat.
HALL	Gives clear vocal and the feeling of a concert
	hall.
PAVILION	Gives the spacious feeling of a pavilion with a
	high ceiling.

These DAP modes can be used to add the acoustic surround effects while reproducing 2 channel stereo source, and can give you a real “being there” feeling.

•When one of the DAP modes is selected, the DSP indicator lights on the display window.

*Manufactured under license from Dolby Laboratories. “Dolby”, “Pro Logic” and the double-D symbol are trademarks of Dolby Laboratories.

**“DTS” and “DTS Digital Surround” are registered trademarks of Digital Theater Systems, Inc.

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