Surround Reference

Dolby Digital

Dolby Digital (earlier called AC-3) delivers five discreet full-range channels (left front, center, right front, left surround and right surround) plus a separate Low Frequency Effects (LFE) channel.

Many soundtracks on the latest generation laser discs, DVDs and High Definition Television (HDTV), are encoded with Dolby Digital technol- ogy.

When a 5.1 channel Dolby Digital program source is playing, such as from a Creative PC-DVD player, the Dolby Digital indicator light will illuminate automatically.

Note: Not every section of a DVD will be 5.1-channel encoded. On many DVDs, only the main movie program will be available in 5.1 channel sound. Other supporting chapters (like a “Director’s Comment” section) may be in stereo or mono. These sections will not light the Dolby Digital indicator even though the sound will be properly reproduced by the DTT2500 Digital.

When listening to DVD movies with

5.1channel Dolby Digital sound, be sure to listen only to the digital program source. You can insure this by:

1.making sure your DVD

player’s stereo downmix is

not sent to your soundcard. For example, disconnect any cable link between the cards.

2.making sure all four CMSS indicator lights are off

(MUSIC, MOVIE,FOURPOINT and STEREO)

3.muting the “CD” input of your computer’s software mixer/ volume control application.

When playing a DVD game with a

mix of Dolby Digital 5.1 sound (a digital signal at the SPDIF input) and soundcard wavetable output (a signal at the analog input), be sure to engage the FOURPOINT mode in the CMSS settings.

Dolby Pro Logic

Dolby Surround is an earlier surround sound standard which is decoded with a Pro Logic processor in the DTT2500 Digital. The Pro Logic steering circuitry derives separate center and rear channels from encoded stereo program sources.

Pro Logic processing provides a convincing movie soundfield when the material is specifically encoded for Dolby Surround. Most older stereo movie soundtracks will only be encoded for Dolby Surround, even though the program source may be a DVD’s digital output. Most DVDs containing Dolby Surround program material will cause both the Dolby Digital and Digital Pro Logic lights to illuminate. DTT2500 Digital will decode these digitally transferred Dolby Surround programs through the digital Pro Logic decoder automatically.

CD-ROMs and CD’s with Dolby Surround encoding will feature the Dolby Surround logo at the beginning of the program or on the packaging. Process these programs by making sure all CMSS indicator lights are off and selecting the Pro Logic Analog Input setting of the Surround Mode button. CD-ROMÕs and CDÕs with Dolby Surround encoding will feature the Dolby Surround logo at the beginning of the program or on the packaging.

Process these programs by making sure all CMSS indicator lights are off and selecting the Pro Logic Analog Input setting of the Support Mode button. Using this Analog Pro Logic Mode to decode Dolby Surround program materia; at the Digital DIN input.

Do not select a Pro Logic decoding mode if the program material is not encoded for Dolby Surround. Excessive center channel output will result, and most stereo effect will be lost. Use CMSS “Movie” or “Music” modes to upmix stereo programs to a realistic 5.1 channel sound field.

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