Lexus GS 450h 2008 Owner's Manual page 301

Setting DSP
The following features can be set as desired by touching
screen.
With CD player
With DVD player
■ Turning Automatic Sound Levelizer (ASL) ON or OFF
Touch
ASL automatically adjusts the volume and tone quality according to the
noise level as you drive your vehicle.
or .
3-3. Using the audio system
on the
3
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