If you don't know what an HD radio is, here's the simple explanation. It's digital radio versus the radio you're listening to today -- which is analog. The advantages of digital radio are many. The two most important are that it produces much better sound than conventional radio. In fact, if you listen to an AM station being broadcast in digital HD, you may think you're listening to an FM station -- that's how clear and static-free the sound is. And listening to HD FM is almost as good as listening to a CD.

The second important advantage of digital HD radio, is that it allows broadcasters to pack more than one channel on the same frequency. These "other" channels are called HD2 channels. As an example of this, we have an FM station in my city that broadcasts easy listening music on its HD1 channel (or primary frequency) and all blues on its HD2 channel.

The Insignia Compact Bookshelf System -- amazing versatility in a small box

While there are a number of tabletop HD radios available, I know of only one bookshelf system. It is the Insignia Compact Bookshelf System, available only from Best Buy. And what this little wonder will do is almost amazing.

Naturally, it does AM/FM/HD radio, including those "hidden" HD2 channels, and, at least to my ears, the sound is just extraordinary. It is one of the few HD radios available with separate speakers so that you can enjoy true stereo sound.

And that's just the beginning

The Insignia unit also plays CDs, including those with MP3 tracks, and DVDs and VCD's. (Note: I currently have an Insignia connected to my HDTV via an S video cable and the picture is outstanding). What's more, there is a dock on the top of the unit for your iPod and a slot to connect USB devices. Plus, it will play MPEG4 discs and JPEG discs.

There are plenty of outputs on the back panel, so you can connect this unit to an amplifier to take advantage of your component system or to other speakers.

A word of warning

I did find some shortcomings in the insignia HD Radio and DVD Player. First, is the users guide. It is fairly helpful, but lacking in certain areas. For example, the instructions for using an MP3 device are missing several important steps. And finding HD2 channels with this unit is more difficult than other units I have experienced. You can set the unit to scan for just HD channels, but you have to look carefully to see when you are on an HD2 channel and then make note of the frequency so that you can come back later to establish a preset. Finally, creating presets is not an easy task. It's a three step process, and you have to have fairly quick fingers to do it correctly.

However, in summation, I cannot think of any other compact system that packs so much versatility in a cabinet measuring just 6.5" x 8.25" x 6.5" and costs less than $150. If you're interested in this unit, do take note of the fact that Insignia is a house brand of Best Buy and available only through the Best Buy website.