Equipped with DSP    

NOTE: THIS OPTION ONLY APPLIES TO BMW MODEL YEARS 2001 AND OLDER

DSP, also known as Digital Signal Processor was an option in the BMW 7 Series, 5 Series and X5. This option is sometimes referred to as TOP HIFI as listed in the BMW option codes.  It is quite easy to tell if you have the DSP audio system by looking at your radio display.  If your BMW is equipped with navigation, look for the menu item that is listed as DSP.  If your BMW is not equipped with navigation, look for the small screen to the right of the tape player that says DSP, or a button that says DSP.

Below are some images of what DSP might look like

Navigation widescreen (smaller 4:3 display will also list DSP as an option)

DSP in BMW 7 Series without navigation

DSP button in X5 or E39 without navigation