What is an FM modulator?

Want sweet iPod tunes in your car, but don't want the static and tinny sound generated by many FM transmitters? There is another way and it doesn't involve an expensive new sound system.

If you want your entire iPod music collection as you're crawling around in peak hour traffic, there are many ways to skin this, proverbial, apple.

Many cars sold in the last few years have built-in 3.5mm auxiliary jacks for clear, static-free iPod connectivity. A lucky few will even find a USB port or two in their rides. Should you find yourself in this crowd, you can look away now.

For the rest of us there are two oft-touted options. The cheap one involves buying an FM transmitter and hoping that you find clear channel space for your usual commute and routes. The more expensive option involves buying and installing a new car audio head unit that has iPod support.

There is another, often forgotten, option: an FM modulator. As we demonstrate in the video above, this device emulates an FM transmission, but goes about it via an altogether different method. An FM transmitter does just that — it takes the output from an iPod and transmits over the air via a low power FM transmitter. This makes it prone to the vagaries of the weather, topology and landscape, as well as by interference from radio stations.

An FM modulator, however, is connected directly to your stereo's aerial port, with the car's aerial connected to it. It then passes on all but a few FM frequencies straight from the airwaves to the car's stereo system; on those frequencies the modulator will transmit, static free via a cable, whatever is playing on your iPod.