Lexus 2008 IS250 Owner's Manual page 226

Sound qual-
ity mode
*
Bass
*
Mid-range
*
Treble
Front/rear
volume
balance
Left/right
volume
balance
Surround
(type B only)
*
: The sound quality level is adjusted individually in each AM FM or CD mode.
Surround (type B only)
n
When the surround mode is on, the matrix 7.1 surround sound system provides a
realistic sound field.
Mode
Level
displayed
"BAS" -5 to 5
"MID" -5 to 5
"TRE" -5 to 5
"FAd" F7 to R7
"BAL" L7 to R7
"SUR-
On/off
ROUND"
3-2. Using the audio system
Press Press
Low
Shifts to rear Shifts to front
Shifts to left Shifts to right
Off
High
3
On
227