While HD radio increases the quality of AM and FM broadcasts dramatically, this may not be the main reason to buy an HD radio.

You may buy it because of a new concept called HD2.

HD radio is digital radio. It requires less radio spectrum which, in turn, enables a concept called multicasting. In other words, radio stations with HD radio technology will be able to broadcast their primary FM channel in digital while offering up to two additional side channels on the same frequency. These extra channels have been named HD2.

What to expect from HD2

Seven of the nation's largest broadcasters have joined together to form the HD Digital Radio Alliance to promote HD radio and to coordinate the use of HD2. One of the goals of this Alliance is to help create new programming content to put on those HD2 signals. The Alliance intends to coordinate the use of the new HD2 channels to offer variety