Rich Warren: A clearer picture on LCD, LED technology

A reader responded to a recent column about LCD versus plasma displays:

"Read your article today about TVs when you said LCD TV is the same as LED TV. I am thinking about a new TV. I still have a nice tube TV, a 40-inch Sony, but it takes up a lot of space."

We never wrote that LCD is the same as LED. First, let's clear up the acronyms. LCD stands for liquid crystal display. LED stands for light emitting diode.

Liquid crystals are tiny window shutters that open and close transmitting or blocking light. A color filter over individual liquid crystals determines the color of its light when it's open. It takes three colors, red, green and blue, to create white light.

Each trio of liquid crystals on your TV creates a single pixel, which is short for picture element. For the LCDs to create a pixel, they require a light source.

Until about six years ago, that light came from a cold cathode tube, akin to an ordinary fluorescent light bulb. These served well, but suffered some problems, including finite life. They could not be pulsed on and off, so in dark areas of the picture some light leaked past the LCD shutters, resulting in dark gray instead of black.

That is why for many years LCD TVs could not compete with plasma TVs. Engineers struggled to produce cold cathode tubes with optimum color temperature (the hue of the light) and brightness.

LEDs surpass cold cathode tubes in every aspect without cold cathode's deficiencies. Even better, LEDs are slightly more energy efficient than cold cathode tubes and last far longer. Initially, LEDs were far more expensive than cold cathode tubes, but their price has fallen significantly, making them competitive.

Thus, in the past three years manufacturers shifted from cold cathode tubes to LEDs. Now only bargain sets use cold cathode illumination. When shopping for a flat-panel LCD TV, choose LED illumination. However, as with all things retail, depending on the price and quality of the set, you may not see all of LED's benefits.

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We recently wrote about the new Bose SoundTouch wireless sound system. You can receive a personal demonstration and hear the system at Picture Perfect Sound, 2909 W. Springfield Ave., C. You also can find the system at some of the big box stores, but you won't hear a decent demonstration.

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Another recent email inquired:

"I've been a Stereophile and The Absolute Sound reader for many years, and a (small-time) collector of audio equipment and appreciator of related equipment and source material for just as long. Can you please recommend any hi-fi or related shops, clubs or similar in the C-U area for a newcomer?"

While Champaign-Urbana is home to fine audio/video dealers, such as Picture Perfect Sound, Good Vibes and Premier, the ultimate audiophiles hang out with Geoff Poor at Glenn Poor's Audio-Video in the Old Farm Shops, 1745 W. Kirby Ave., C (not to be confused with the service shop on Springfield Avenue in Urbana). Poor also is a principle in Balanced Audio Technology, a small, ultra-high-end manufacturer of classic vacuum tube equipment.

I have no personal or business relationship with Poor or any local dealers, other than spending time enjoying their wares in their stores. Well, actually, I bought a sound system from Good Vibes when it first opened on Green Street, circa 1972. It's now on Prospect Avenue near Bloomington Road.

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Finally, I recently met again with the media relations person from Comcast. He once more extended the invitation to play ombudsman for any reader issues with Comcast.

He emphasized that everyone who works for the company is evaluated by how much and how well he or she helps subscribers. I do not receive Comcast service and have no vested interest in the company.

Rich Warren, who lives in the Champaign area, is a longtime reviewer of consumer electronics. He can be emailed at hifiguy@mchsi.com.

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