Connecting a Car CD Changer to a Factory Stereo

Spindles of compact discs

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It's possible to use a CD changer in conjunction with any head unit, factory or aftermarket. Your options will vary depending on whether your head unit was designed for use with CD changers and/or other auxiliary inputs, but they’ll be pretty similar overall to the options for using an iPod with a factory stereo. If your head unit doesn’t have the right inputs, you can still hook in a CD changer with an FM transmitter or an RF modulator.

You can have the work done by a dealer if you want to, but you don’t have to. Any good car audio place will be able to do this type of installation for you, and it’s even something you can do yourself if you’re comfortable with removing your head unit and doing a little wiring.

Factory Head Units and CD Changers

Just like aftermarket receivers, some factory head units are actually designed for use with CD changers and other auxiliary inputs. It isn’t always clear that a head unit has this ability, either, so you may want to contact your local dealer to ask. If your local dealer isn’t helpful, you might have luck with a local car audio place if they have any experience with your make and model. You can also check into whether there are any popular Internet forums for enthusiasts of your particular make or model of the vehicle and ask there.

If your head unit was designed for use with a CD changer, then the process of adding one is usually going to be fairly painless. You may need to obtain a proprietary input cable from a dealer or a reseller. Depending on the CD changer you choose, you may also need to buy some sort of an adapter. In either case, factory head units with this capability are typically capable of controlling CD changers as well, so this is the best, cleanest way to go.

FM Transmitters and RF Modulators

FM transmitters and RF modulators are two of the ways that you can connect just about any audio source, including a CD changer, to virtually any head unit. The one caveat is that the head unit has to be a receiver or tuner, not a controller. That basically just means that the head unit has to include a radio. It’s also important to note that the radio has to include an FM tuner.

Although FM transmitters are easier to use than RF modulators, they’re not the best way to go if you’re installing a CD changer. The main benefit of an FM transmitter is that you don’t actually have to install it, which means it’s portable, and you can move it from one car to another (or remove it altogether) easily. This is due to the fact that it works by transmitting the audio signal from your input device (a CD changer in this case) via an FM radio frequency, which is picked up by the tuner in your head unit. Of course, that means that these devices are subject to interference, and the sound quality isn’t always that great.

FM modulators are more permanent, in that they introduce an FM signal directly into your head unit via the antenna cable. That means they are more difficult to install, but it also means the sound quality is better. So unless you plan on moving your CD changer from one car to another regularly, you’ll probably want to go with an FM modulator.

FM Modulators and CD Changer Controls

The main drawback of using an FM modulator versus a head unit that’s actually designed for CD changers is the lack of controls. When you hook up a CD changer to a head unit that’s designed for it, you can switch discs, select tracks, and perform other functions with the native head unit controls. Since an FM modulator just introduces an audio signal via a head unit’s antenna jack, that functionality is lost.

When you use an FM modulator to hook up a CD changer, you essentially have to use a separate controller to operate the changer. You tune the FM dial to the appropriate frequency (usually something like 89.1), which causes the head unit to play whatever audio signal is sent from the CD changer. You then select a CD and track via the separate controller, which can be either wireless or wired, depending on the changer.

Although many aftermarket CD changers come with the necessary controller, and some even come with an FM modulator, this isn’t always the case. That makes it important to verify exactly which components you're going to get before you choose a CD changer. If the changer you’re looking at doesn’t come with a wired or wireless controller, then it’s even more important to verify that one is actually available before you make a purchase.