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Challenges to using the iPod in your car
Check out any iPod forum online (there are tons — iPodlounge.com is one of the best) and you'll find hundreds of comments from frustrated iPod enthusiasts trying to connect an iPod to their car stereo. The same topics and questions seem to keep coming up:
- Installation: How do you physically transmit the audio signal from the iPod to your car stereo?
- Power: The iPod's Achilles' heel is its short battery life. How can you get power to the iPod in the car?
- Control: Despite its ingenious user interface design, the iPod wasn't designed to be used while driving a car. How can you safely scroll through your iPod playlists while cruising down the road?
- Sound Quality: The tunes stored on your iPod are most likely already in a compressed format (AAC files), so any degradation of sound quality while transmitting the audio signal to your car stereo will have a significant impact on how your music sounds. What's the best way to preserve the sound quality of your iPod tunes?
Currently, if you want to listen to your iPod on your car stereo, you've got four options from which to choose: direct connection via auxiliary input, wired FM modulator, wireless FM transmitter, or cassette adapter. Each option offers a different level of sound quality and degree of installation difficulty, but none allow you to operate the iPod with your receiver's controls.
 You need a stereo-minijack-to-stereo-RCA cable to connect an iPod to an Aux input. |
Connecting an iPod via auxiliary input
It's extremely rare for a factory stereo to have an auxiliary input, so this method is primarily for iPod owners with an aftermarket car stereo. Connecting your iPod to an auxiliary input provides optimal sound quality and is always the best method to use when possible. Unless your receiver offers a front-panel auxiliary input (fairly rare), you'll have to remove the receiver to access the back-panel input. Many aftermarket receivers have aux in capability, but depending on the make and model, you may need an adapter to convert the CD changer port into an auxiliary input. Even with the auxiliary input, you'll still need to use a cigarette lighter power adapter or optional battery pack to keep the iPod from draining its battery. You also have to use the iPod to scroll through your playlists, which is not a great idea while driving.
BMW has recently introduced a factory-installed iPod adapter for 2002-and-up 3 Series, Z4 Roadsters, and X3 and X5 SUVs. The BMW solution provides excellent aux in sound quality, but it stumbles in other areas. Because this is a factory-only option, BMW owners have to pay dealership installation prices to get the iPod adapter. In addition to the $149 price tag for the adapter itself, BMW owners must pay factory labor costs — my local BMW dealership charges $95 per hour and estimates 2 hours of installation time. Still, you figure most BMW owners can afford to splurge a bit on the luxury of controlling the iPod from their steering wheel stereo controls. The bigger problem with the BMW adapter is its inability to display all the playlist, artist, and song information used to navigate through an iPod song collection. Instead, the the user must create 5 special BMW playlists. Walter Mossberg, The Wall Street Journal's Personal Technology columnist, sums up the BMW iPod interface this way: "The BMW iPod adapter works, but in a pretty crude way that will likely leave the iPod cult hungering for more."
 An FM modulator connects between the antenna and the car stereo. |
Wired FM modulator
A wired FM modulator provides sound quality as good as your best FM radio reception. FM adapter devices (wired modulator or wireless transmitter) can be used with any car stereo, factory or aftermarket, as long as it has an FM radio. The major drawback to a wired FM modulator setup, aside from the slightly diminished sound quality, is the difficulty of installation. You have to connect two power wires (switched and constant) and a ground wire; you also need to run the vehicle's antenna lead into the modulator box. None of this is particularly difficult to do (see our Peripherals Installation Guide for instructions), but it does require removing your stereo and mounting the modulator box. And of course, you must use the iPod to navigate through playlists, and use a cigarette lighter adapter or battery pack to power the player.
 Monster Cable's iCarPlay Wireless FM transmitter. |
Wireless FM transmitter
A wireless FM transmitter is much easier to install than a wired modulator — it uses a either a cigarette lighter power adapter or batteries, so you don't have to tap into power or ground wires. But what the wireless transmitter gains in convenience, it loses in sound quality. Wireless transmitters are susceptible to interference and static, especially in large cities, and generally deliver a slightly weaker audio signal than a wired modulator. There is at least one wireless FM transmitter for iPods that allows you to charge the iPod and transmit the audio signal on an FM frequency with a single connection (Monster iCarPlay Wireless for $69.99).
 Belkin mobile cassette adapter. |
Cassette adapter
Does anybody still have a cassette player? Yes, quite a few people do, and those folks can use a cassette adapter to pipe the iPod's audio signal to their car speakers. Cassette adapter kits are simple to install, but they do tend to leave a tangle of wires hanging over your dash. Power is supplied from a cigarette lighter power adapter. Sound quality for cassette adapters is fair.
For more information on the pros and cons of each in-car iPod setup, see Jim Richardson's article "Going Mobile with iPod."
