A music file normally goes from the iPod's memory to its digital-to-analog converter (DAC), where it's processed and sent to your headphones. Some car stereos can take a file directly from the iPod to process it with their more advanced DACs. The end result is better sound.
To receive digital audio broadcasting, you will need an HD Radio tuner. Some receivers have the tuner built-in, while others have the option to add a tuner.
The receiver is compatible with optional components that will receive digital satellite radio broadcasts such as Sirius or XM Satellite Radio. The digital satellite service must be subscribed to separately.
Lets you tune to the European interval of .05 kHz. If a receiver has European tuning, it can be used in many countries overseas. All models available from Crutchfield will tune to all US FM and AM frequencies.