Sony WEGA KLV30XBR900 Operating Instructions Manual page 82

> Select to turn on the TV speakers.
.... Select to turn off the TV speakers and listen to the
TV's sound only through your external audio
system speakers.
> This option can be set only when the option is set to
Easy control of
volume The TV's speakers are turned off, but the audio
adjustments output from your audio system can still be
controlled by the TV's remote control.
The TV's speakers are turned off and the audio
output of the TV is fixed. Use your audio
receiver's remote control to adjust the volume
(and other audio settings) through your audio
system.