Sound quality is probably not the first thing that comes to mind when you think of an iPod. Ease of use, and "cool factor" have been the main accolades to propel Apple to a 75 percent plus market share of dedicated digital music players. Many of today's youth have never sat in front of a high-end home system or in the driver seat of a great SQ car. Instead they were raised on ear buds, computer speakers and home-theater-in-a-box. With over 100 million units sold, it looks like people love them regardless of their reputation for lackluster sound quality. It might be a bad rap. So let's take a look at playing your iPod through your car stereo and how you're loading content onto your portable device.
Getting Hooked Up
What ways are there to get sound out of your iPod? The first and most obvious (common to all iPods) is the headphone jack. Since the music is stored digitally it will need to be converted to analog using the built-in D/AC (digital-to-analog converter). Now that the signal is analog it will be routed through a small amplifier and out to the standard 3.5mm stereo headphone mini-jack. Next, we need to get that sound into your car stereo.
There are several ways to accomplish this goal. First are the two least desirable ways - a cassette adapter or FM modulator. These devices plug into the 3.5mm jack and transmit the signal to the source unit in your vehicle. I'm assuming that if you're reading this you've either tried this and were disappointed, or it would never be an option for you!
Fortunately, several new cars and aftermarket radios now come with an aux input. This can be in the form of an easily accessible 3.5mm stereo jack or stereo RCA input connection. In both cases all you need is an inexpensive cable to connect the audio out of the iPod to the aux-in of your source. While this is a huge upgrade over the two aforementioned options, it still leaves room for improvement.
Let's look at ways to improve both performance and usability. Remember the process of amplifying the signal meant to power the headphones? Well, all amplifiers produce distortion. Although Apple has done a fair job keeping distortion minimal, there's also a chance to overdrive or "clip" your aux input if the volume level of the iPod is set too high. Fear not - there are ways to get around these issues.
So how do we get around that amplifier? At the bottom of an iPod (except the Shuffle or older iPods) is the docking interface connection. By using a dock connecter you can bypass the internal amplifier and volume control. The most basic of interface adapters plug into this pin-out and output an analog signal via stereo RCA connectors, all the while bypassing the volume adjustable 3.5mm jack. Instead, the docking interface outputs are at a set level that is source dependant for volume control. Often these cables are also available with a cigarette lighter plug to charge your iPod while driving. A custom install shop can also hardwire the plug so you don't use up your main power supply in the front of your car.
Higher-end aftermarket radios offer direct connections that actually allow full control of your iPod through the head unit and display track/artist information on the radio. They also allow for a level-matched input and for charging of the iPod itself. Devices are also available to give a similar experience with some newer factory radios. Although some are faster and easier to use, these products allow for the iPod to be stored securely (and for your concentration to be on the road).
The newest, latest and greatest for aftermarket radios were introduced at the Consumer Electronics Show in January. New head units like Pioneer's DEH-P6900UB offer a USB digital connection between the radio and iPod.
Alpine's iDA-X001 goes one step cooler by displaying album art on its high-resolution display. These units both use built-in D/ACs to convert your stored digital files internally and bypassing any sound-affecting processes inside the iPod.