2009 Toyota 4Runner Owners Manual - Page 290

3-2. Using the audio system Mode displayed BAS MID TRE FAD Sound quality mode Bass* Mid-range* (type C only) Treble* Front/rear volume balance Left/right volume balance Level -5 to 5 -5 to 5 -5 to 5 R7 to F7 Turn to the left Turn to the right Low High Shifts to rear Shifts to front BAL L7 to R7 Shifts to left Shifts to right 3 *: The sound quality level is adjusted individually in each radio mode or CD mode. Interior features n Adjusting the Automatic Sound Levelizer (ASL) Type A and B When ASL is selected, turning to the right changes the amount of ASL in the order of LOW, MID and HIGH. Turning to the left turns ASL off. ASL automatically adjusts the volume and tone quality according to vehicle speed. Type C When ASL is selected, turning turning to the right turns ASL on, and to the left turns ASL off. ASL automatically adjusts the volume and tone quality according to the noise level as you drive your vehicle. 267