2003 GMC Sierra 1500 Pickup Owner's Manual - Page 255

Setting the Tone (BasdTreble) AUDIO: Push the AUDIO knob until BASS, MID or TREB appears on the display. Turn the knob to increase or to decrease. If a station is weak or noisy, you may want to decrease the treble. To adjust bass, midrange or treble to the middle position, select BASS, MID or TREB and push and hold the AUDIO knob. The radio will produce one beep and adjust the display level to zero. 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. The radio will produce one beep and CENTERED will appear on the display. AUTO EQ (Automatic Equalization): Press this button to choose between bass, midrange and treble equalization settings designed for country, jazz, talk, pop, rock and classical program types. To return to the manual mode (CUSTOM), press the AUTO EQ button until CUSTOM appears on the display. Then you will be able to manually adjust the bass, midrange and treble using the AUDIO knob. If your vehicle is equipped with the Bose@audio system, your equalization settings are either CUSTOM or TALK. Adjusting the Speakers (BalanceFade) AUDIO: To adjust the balance between the right and the left speakers, push the AUDIO knob until BAL appears on the display. Turn the knob to move the sound toward the left or the right speakers. To adjust the fade between the front and rear speakers, push and hold the AUDIO knob until FAD appears on the display. Turn the knob to move the sound toward the front or the rear speakers. To adjust the balance and the fade to the middle position, select balance or fade and push and hold the AUDIO knob. The radio will beep once and will 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 controls are displayed. The radio will produce one beep and CENTERED will appear on the display. 3-100