A compact disc (CD) changer is a CD player that can hold multiple compact discs at once. Models made for home stereo systems are integrated into the CD deck itself, and generally use a carousel style tray that can hold five or six discs. A CD changer for automobiles is a separate unit that works in conjunction with the in-dash player or factory radio. In a sedan, mobile CD changers are normally installed under a seat or in the trunk. In sports utility vehicles, they might be located behind a rear side panel.

There are two main types of mobile CD changers: standard and FM modulated. The in-dash deck and the deck’s wireless remote can control a standard CD changer. An FM modulated CD changer is made to work with a factory radio that does not have built-in CD controls, and therefore requires its own hard-wired LCD display and wireless remote.

When purchasing an aftermarket car stereo, note that not all units have the ability to control a separate CD changer, even if the deck plays CDs itself. To control a separate changer with the deck’s controls and wireless remote, the unit must have a feature set that includes CD controls. Additionally, you must purchase a CD changer that is compatible with the in-dash deck. Commonly this means buying a changer made by the same manufacturer.

If you would like to avoid the hassle of changing your in-dash unit, but would like a CD changer, the FM modulated CD changer might be the answer. You won’t be able to control the CD changer with the in-dash unit or its remote, but the CD changer itself will come with a hard-wired LCD display and controls, plus a wireless remote.

FM modulated or standard, a mobile CD changer uses a magazine to hold multiple CDs, rather than a carousel tray. This not only allows the mobile changer to be more compact, it also allows it to hold more CDs than a carousel-style CD changer. The smallest mobile changer holds six CDs, and larger models hold twelve CDs or more.