GMC 2005 Envoy Owner's Manual page 202

Setting the Tone (Bass/Treble)
AUDIO: Push and release the AUDIO knob until BASS,
®
MID (without Bose ), or TREB appears on the display.
Turn the knob to increase or to decrease. The display will
show the bass, midrange (without Bose
If a station is weak or noisy, decrease the treble.
To adjust the bass, midrange (without Bose
the middle position while it is displayed, push and hold
the AUDIO knob. The radio will produce one beep and
adjust the display level to the middle position.
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 audio system, the
AUTO EQ settings are either CUSTOM or TALK.
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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
®
), or treble level. move the sound toward the right or the left speakers.
To adjust the fade between the front and the rear
®
), or treble to 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.
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.