2006 Lexus IS 350 Navigation Manual - Page 166

IS350/250_Navi_U (L/O 0508) 166 AUDIO/VIDEO SYSTEM D DSP control To display the DSP control mode screen, touch "DSP" on the audio control mode screen. " With CD changer Surround function (DVD changer only): Select "ON" of "SURROUND" and touch "OK". The surround function will turn on. Automatic sound levelizer (ASL): When the audio sound becomes difficult to hear due to road noise, wind noise or other noises while driving, touch "ON". The system adjusts to the optimum volume and tone quality according to the noise level. When the system is on, the sound adjustment level is displayed on the screen. Positioning selector (CD changer only): By selecting the listening position, the system controls the output timing of the speakers to allow sound to be heard evenly, creating the ideal music environment. Touching "CHANGE" switches the position in the following order: all seats, driver's seat, front seat, rear seat. The position currently selected is displayed on the screen. " With DVD changer You can turn on/off the surround or the automatic sound levelizer on the DSP screen.