GMC Sierra 2005 Owner's Manual page 242

To adjust all tone and speaker controls to the middle
position, push and hold the AUDIO knob when no tone
or speaker control is displayed. ALL CENTERED will
appear on the display, you will hear a beep, and
the display level will be adjusted to the middle position.
AUTO EQ (Automatic Equalization): Press this
button to select customized equalization settings
designed for country/western, jazz, talk, pop, rock, and
classical. Selecting CUSTOM or changing bass or
treble, returns the EQ to the manual bass and
treble settings.
The radio will save separate AUTO EQ settings for each
preset and source.
If the radio is equipped with the Bose
the equalization settings are either CUSTOM or TALK.
Adjusting the Speakers (Balance/Fade)
AUDIO: To adjust the balance between the right
and the left speakers, push and release the AUDIO
knob until BAL appears on the display. Turn the knob to
move the sound toward the right or the left speakers.
To adjust the fade between the front and the rear
speakers, push and release the AUDIO knob until FADE
appears on the display. Turn the knob to move the
sound toward the front or the rear speakers.
3-74
To adjust the balance or fade to the middle position,
while it is displayed, push the AUDIO knob, then push it
again and hold it until the radio produces one beep.
The balance and fade will be adjusted to the middle
position and the display will show the speaker balance.
To adjust all tone and speaker controls to the middle
position, push and hold the AUDIO knob when no tone
or speaker control is displayed. ALL CENTERED will
appear on the display, you will hear a beep, and
the display level will be adjusted to the middle position.
Finding a Program Type (PTY)
Station (RDS and XM™)
To select and find a desired PTY perform the following:
®
audio system,
1. Press the TYPE button to activate program type
select mode. TYPE and a PTY will appear on the
display.
2. Turn the TYPE knob or press and release the
TYPE button to select a PTY.
3. Once the desired PTY is displayed, press and
release either the TYPE or the SEEK arrows to
select and to take you to the PTY's first station.