Lexus 2003 LS Owner's Manual page 220

AUDIO
20L344
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) Tone and balance
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.
A good balance of the left and right stereo channels and of the
front and rear sound levels is also important.
Keep in mind that if you are listening to a stereo recording or
broadcast, changing the right/left balance will increase the
volume of one group of sounds while decreasing the volume
of another.
206
20L125
"BALANCE" knob: Use this knob to adjust the sound
balance between the right and left speakers.
"FADER" knob: Use this knob to adjust the sound balance
between the front and rear speakers.
"BASS" knob: Use this knob to adjust low–pitched tones.
"MID" knob: Use this knob to adjust mid–pitched tones.
"TREBLE" knob: Use this knob to adjust high–pitched tones.