AVI 250 (serv.man9) - Harman Kardon Audio User Guide / Operation Manual. Page 33

Advanced Features

27

DOLBY PRO LOGIC

Dolby Pro Logic is the standard mode for surround sound decoding. It uses information 

15 ms – 30 ms

encoded in a two channel stereo recording to produce four distinct channels: 

Initial Setting = 20 ms

Left, Center, Right and Surround. Use this mode for accurate reproduction of 
programs bearing the Dolby Surround, DTS Stereo, UltraStereo or other “Surround” 
logos. Surround encoded programs include videocassette and LD movies, TV and 
cable programs, radio programs and audio CDs. Dolby Pro Logic processing 
may also be used to provide a pleasing surround effect with source material that 
does not carry surround encoding.

THX CINEMA

THX Cinema is a patented process developed by Lucasfilm Ltd. as an enhancement 

15 ms – 30 ms

to surround processing. It includes additional enhancements that greatly improve 

Initial Setting = 20 ms

the spectral and spatial realism of motion pictures that are recorded with surround 
encoding. THX Cinema’s exclusive processing is designed to overcome the differences 
in acoustics between movie theaters and home listening rooms so that movie sound 
tracks will sound the same way at home as they did in the mixing room where they 
were created. Use this mode when viewing motion pictures on video.

DOLBY 3 STEREO

Dolby 3 Stereo uses the information contained in a surround encoded or stereophonic 

No Surround Channels

program to create center channel information. In addition, the information that is 
normally sent to the rear channel surround speakers is carefully mixed in with the front 
left and right channels for increased realism. Use this mode when you have a center 
channel speaker, but no surround speakers.

MOVIE SURROUND

Movie Surround processing features surround decoding with the option to extend the 

40 ms – 90 ms

delay time to 90 ms. This mode can be used in very large rooms, or to experiment with 

Initial Setting = 40 ms

delay times greater than 30 ms.

HALL SURROUND

This mode is designed for use with stereo recordings. It provides a sound field effect 

10 ms – 90 ms

that simulates the complex combination of direct and reflected sounds that create 

Initial Setting = 20 ms

the rich reverberant atmosphere of a medium sized circular concert hall.

MATRIX SURROUND

This mode is designed for use with sports broadcasts, live concerts or other programs 

10 ms – 90 ms

where the feeling of a wide surround effect is desired.

Initial Setting = 20 ms

MONO

This mode is intended for use with old movies, televisions shows and other programs

No Surround Channels

that have a monaural sound track. All sound will be reproduced through the center 
channel speaker, if installed. If there is no center channel speaker, monaural sound is 
reproduced from the front left and right speakers.

STEREO

This mode turns off all surround processing and presents the pure left and right 

No Surround Channels

channel presentation of two channel stereo programs.

Surround Mode Chart

Engelsk manual AVI250  11/01/98 8:53  Side 27