Television - Making the Sound as Good as the Picture

There are so many decisions to make when buying a TV…screen size, HD-compatibility, picture quality…that we sometimes forget the importance of a great sound system. If creating a theatre-like entertainment experience in your home is what you’re working toward with the purchase of a new TV, then it is true that sound can make or break your viewing experience. It’s hard to discuss sound and home theatre without discussing Dolby Digital 5.1 audio, surround sound. HDTV is capable of broadcasting programs in this format and newer Home Theatre technology can create an invigorating experience by inundating your senses with incredible sound making you feel more like a participant than a spectator.

The “5” in Dolby Digital 5.1 audio refers to the five channels of amplified sound for the five distinct sections of the listening area: front left, front right, front center, rear left (also known as “left surround channel”), and rear right (also known as “left surround channel”). The “.1” refers to the Low Frequency Effects (LFE) channel. This is a sixth channel that is usually unamplified and feeds the subwoofer, an independently amplified, low-frequency-optimized speaker.

Let’s take a closer look at the audio equipment that makes up this unique system that brings us the definitive sound experience of Dolby Digital 5.1 audio.

THE RECEIVER
The ability of Home Theatre receivers to process and amplify multiple channels of audio (Dolby Digital 5.1 audio) is what separates them from other audio systems. A receiver must be able to decode one of the two most-used surround formats, DTS or Dolby Digital decoding technology, both of which are excellent for bringing the viewer the multichannel, surround sound experience.

An option to buying a receiver with built-in decoding technology is a Dolby Digital-ready receiver. This type of receiver doesn’t have decoding circuitry, but does amplify multiple channels of Dolby Digital audio generated by decoders in newer DVD players. Even though this is a more economical option, a Dolby Digital-ready receiver can only decode audio on discs and not from any other sources, including digital broadcast media. Buying a receiver with built-in Dolby Digital or DTS decoding technology is recommended.

THE SPEAKERS
A two speaker stereo system cannot produce 5.1 channels of audio. A stereo system can be incorporated into a 5.1 audio system as front right and front left components as long as they have the magnetic shields necessary to contain the magnetic fields generated by the drivers that can interfere with the TV’s picture. You will still need a 3-piece add-on system with two satellite speakers for left and right surround channels and a center channel speaker.

Many consumers are concerned with the amount of space a surround sound system could take up in their TV rooms. Some newer systems can be great for sound without taking up the whole room. You can now find various 5-piece speaker systems that are more conspicuous. These systems consist of four identical compact, full-range speakers and a fifth speaker for the center channel. The magnetic shields needed to prevent picture distortion are usually incorporated into the system.

THE CENTER CHANNEL SPEAKER
The center channel speaker delivers more than half of the audio content for movies, including the dialog, making it necessary for manufacturers to pay particular attention to detail with this speaker. Some stand-alone designs are available and some can be added as an upgrade to multiple-piece systems. Strong magnetic shielding is a must in their design.

THE SUBWOOFER
The purpose of an LFE channel (the sixth channel that makes up the “.1” in Dolby Digital 5.1 audio) is to provide a powerful sound that we hear and feel as we watch our favorite movies. The addition of these low-frequency effects can take home entertainment to the next level. The best are high powered (75-100 watts) with low distortion and a phrase-reverse switch with adjustable crossover frequency to allow you to adjust the system to your room for premium performance.

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