2006 Pontiac GTO Owner's Manual - Page 151

Speed-Dependent Volume (SDV) With SDV, the audio system adjusts automatically to make up for road or wind noise as you drive. This feature will never completely compensate for driving noise. There are other factors such as road surface, wind noise, windows open, and engine speed that may alter the interior noise for any given road speed. You can select compensation rates between 0 (off) and 5 (maximum compensation) in the options menu. See "Options Menu Adjustment" later in this section to adjust SDV. The speakers may go off when the volume level is set at a high or full volume for a long period of time in order to protect the amplifier from overheating. When the amplifier cools down, the radio will reset and you will again hear sound through the speakers. The main source of distortion in music is the low frequency bass caused by drums or large instruments. Music that features very strong bass may trigger the distortion limiting system and the system will then reduce the volume to minimize the distortion. Increasing the bass control or the EQ boost may also result in a reduced volume level due to the emphasized bass. See "Setting the Tone (Bass/Treble)" previously in this section. The DDL can be turned off so that the radio will deliver a higher volume level, but distortion will also be increased. See "Options Menu Adjustment" later in this section to adjust DDL. Dynamic Distortion Limiting (DDL) The radio has a feature that limits the amount of amplifier distortion that you can hear. When this feature is turned on, it continuously monitors the quality of the signal to the speakers. When the signal distortion exceeds the preset limits the radio will automatically limit or reduce the volume until the distortion is minimized. Under some circumstances, distortion may be heard for a very short period of time until the system has taken the necessary steps to limit it. 3-53