First post in a series of articles exploring easily misunderstood A/V terms

What do you think the word "sturdy" means?  Strong? Tough? Stable?  Sure. That's what sturdy means now. Did you know it originally described someone who was "stubbornly stupid, giddy, and thoughtless?"   Meaning shifts happen all the time, especially in technology, and common sense reasoning doesn't always help. New ways of living, scientific advances, faulty translations, pop culture, obscure jokes and even sarcasm all play into a word's transition from one meaning to another. A field like Consumer Electronics is particularly prone to poorly understood "techy" jargon and terms that have lost or changed their meaning over time. 

The real confusion begins when overlapping technologies lay claim to the same term. Consider "HD," for example:

Anyone who's into A/V gear has heard the terms "HD" and "HiDef" being bandied about more or less interchangeably for a couple years now.  We know HD is an all-digital format, and digital technology is generally recognized as a cleaner, better-looking signal. So it would make sense if the "D" in HD stood for "digital", right?  Welllll....no. In most cases, the "D" in HD stands for definition, and refers to one of several digital video formats, all of which pack more visual information into a single image on your TV screen...then there's HD Radio. 

See, about the same time that High Definition Multimedia Interface (HDMI) technology and High Definition Television (HDTV) came out, so did a cool new thing called HD Radio. HD Radio is not high definition, but it is digital.  So does the "D" stand for digital here? Yes and no. The "HD" part originally referred to what this kind of radio transmitter does (it broadcasts a Hybrid radio wave made up of both Digital and analog signal) but now, HD Radio is a brand name, nothing more.  

Each one of the HD formats work on a different principal, and produce a different effect. 
 

High Definition refers to density or resolution - ie, the amount of information that can be packed into a single transmission. The more information, the better, that's the theory. There are way too many formats to get into here, but a few of the big ones include:

• HiDef is a digital video format, generally used in camcorders. It captures video at 24 frames-per-second - the speed at which movies are filmed - so you can get near cinema-quality video. 

• HDMI is a different digital format, this time for transmitting uncompressed, digital signal (audio and video) in home theater systems. The all-in-one, all-digital capability was once considered the Holy Grail of Home Theater. The fact that it can carry both signal types makes it very cool, but the real "wow" factor comes from the cable's ability to pass uncompressed digital signal (less compression = more signal = higher fidelity and a better picture...in short, home theater goodness). If you're thinking of upgrading your system, it pays to find out more about this format. HDMI.org offers an in-depth faq on the subject, along with educational articles and resources for installers.

• HDTV is one of several digital formats currently available for broadcasting digital TV signal. CNet.com has a short article about HD resolution, and for a really enthusiastic dose of information on all things "DTV" check out  HDTVinfoport.com.

HD Radio is a little different. Yes, you're listening to a digital signal, but unlike the formats mentioned above,  HD Radio transmitters compress it to fit the subcarrier frequency it's assigned to. The cleaned-up digital signal is better than FM (and comparable to satellite radio), but it's by no means high definition. The digital/FM hybrid signal sounds better because the digital portion of the broadcast is much cleaner. In terms of detail, what you're hearing is roughly the same as what you'd expect from a 96-128 kbps MP3 file.

The biggest advantage HD Radio offers is expanded content and services. HD Radio transmitters allow terrestrial stations to slice their frequencies into smaller chunks, so the same station can broadcast two or more "channels" of content along with their regular (analog FM) content, including text information like song titles, station identification or emergency alerts.  If that sounds familiar, it's because cable television started doing something similar five years ago.

In the end, all these HD technologies offer a cleaner, clearer, better-looking (or sounding) signal than is usually possible with analog transmission. You can learn more about all HD formats when you explore our learning center.

What terms trip you up? Let me know. We'll explore together.