Lexus 2008 IS250 Owner's Manual page 225

3-2. Using the audio system
Adjusting the Automatic Sound Levelizer (ASL)
Press
The ASL switches between on and off modes each time the switch is
pressed.
ASL automatically adjusts the volume and tone quality according to the noise
level as you drive your vehicle.
Changing the listening position (type A only)
The sound feel setting can be changed to produce the best sound for
each listening position.
Press
The display changes as follows each time the button is pressed.
Display
"DRIVER"
"FRONT"
"REAR"
"ALL"
Adjusting sound quality and volume balance
Changing sound quality modes
n
Press
Pressing the button changes the sound mode in the following order.
"BAS" "MID" "TRE" "FAd" "BAL" "SURROUND" (type B
only)
Adjusting sound quality
n
Press
226
.
(position selector) to change the setting.
Position best suited to the driver' s seat
Position best suited to the driver' s and front passenger
seats
Position best suited to the rear seats
Position best suited to all seats
or to adjust the level.
Listening position