Service manual

Audio Processing
The sound processing in N8 is completely done by the MSP3451G for 'Virtual Dolby'
sets:
• Volume control is done by the user via the SOUND menu.
• Tone control is done via the BASS/TREBLE control.
• Headphone control : In 'Virtual Dolby'-sets, the MSP has a separate Headphone
output so separate sound control is possible.
• Mute control can be done in different ways:
§ Via the 'SOUND_ENABLE' line of the Painter. Used during start-up/switch-
off conditions, in order to avoid audible plops. This line is active low (high
= mute).
§ Via the decoding part of the MSP.
§ Via the processing part of the MSP.
The mute on the RC transmitter or in the User Interface (UI) is per today a combination
of processing mute and 'SOUND_ENABLE' line. When a user mute is done, the
processing mute will turn down the volume, after which the 'SOUND_ENABLE' line is
switched. De-muting is the other way around. The reason for this is a technical problem
with crosstalk of the headphone into the loudspeakers.
Automatic Volume Leveling (AVL)
One of the features of the MSP-family is AVL. If used, it limits the big volume
differences in the broadcast between e.g. news transmissions and commercials or
within a movie.
To be able to get a Dolby approval (for the Virtual Dolby sets), the AVL feature must be
switchable. Therefore, the AVL feature is customer switchable via the menu.