Toyota Lexusc Owner's Handbook Manual page 319

AUDIO
In the "TAPE" or "CD" mode, the applicable functions are
shown in the lowest part of the display. Push the switch
just below to turn on each function.
(b) Adjusting audio sounds
Your audio system can adjust tone and sound balance
or select the listening seat position.
How good an audio program sounds to you is largely
determined by the mix of the treble, mid-range, and bass
levels. In fact, different kinds of music and vocal programs
usually sound better with different mixes of treble, mid-range
and bass.
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Adjusting the sound balance and selecting the listening seat
position is also important for good an audio sound.
Keep in mind that if you are listening to a stereo recording or
broadcast, changing the sound balance or listening seat
position will increase the volume of one group of sounds while
decreasing the volume of another.