Understanding Surround Sound Systems

Surround sound is the concept of expanding the spatial imaging of audio playback from 1 dimension (mono/Left-Right) to two or three dimensions. It is often employed for a more realistic audio environment, actively implemented in cinema sound systems, technical theatre, home entertainment, video arcades, computer gaming, and a growing number of other applications. Many popular surround sound formats have evolved over the years. They include ambisonics, quadraphonic, Dolby 5.1 Surround sound, DTS, and MP3 Surround.

Surround sound can be created using several methods. The simplest to understand uses several speakers around the listener to play audio coming from different directions. Another approach involves processing the audio using psychoacoustic sound localization methods to simulate a 3D sound field using headphones. The third approach, wave field synthesis, uses a very large number of speakers to generate the "audio hologram" of the original audio in the whole room (as of 2004 the only commercial implementation of this is Iosono). Surround sound is not limited to placement of speakers along a flat (2-dimensional) plane. Vertically-located audio sources can be considered.

Dolby Digital (DD) uses the AC-3 file format, which any Dolby Digital Decoder can decode to produce 5.1 audio. Dolby Digital is the technical name for Dolby's multi-channel digital sound coding technique, more commonly referred to as Dolby 5.1. A six-channel sound coding process originally created by Dolby for theaters, AC-3 was subsequently adapted for home use and is now steadily becoming the most common sound format for DVD.

Six discrete audio channels:

•3 for speakers at the front - left (L), center (C), and right (R)
•2 for surround speakers at the side or rear - surround left (SL) and surround right (SR)
•1 low-frequency effects (LFE) channel carries supporting deep bass sound effects, ranging from 10 Hz to 120 Hz, which can for example be used by a subwoofer. (This is the '.1' in '5.1'.)

DTS is an encode/decode process that delivers 5.1 channels of "master quality" audio on CD, CD-R, and DVD. Each DTS encoded disc represents a sonic "clone" of the original film soundtrack.

The difference between Dolby Digital (AC-3) and DTS is:

•DTS provides a deeper and tighter low frequency presence
•DTS allows the sound to breath - transparency
•AC-3 leaves the impression that something is missing from the mix
•At lower bit-rate AC-3 starts to sound like MP3's encoded at a low-quality 96kbps
(artifacts)

DTS is more three dimensional. The sound actually moved forward from the individual speakers to sound more full. This fullness was most apparent with the music. Instead of simply coming from the speakers, the DTS filled the front soundstage not only side to side, but with more depth as well. Bass reproduction was also more defined in the DTS version, leaving the DD edition sounding muddy.

Dolby Digital incorporates dialog normalization, which alters the decoded level of the soundtrack. The typical setting reduces level by 4 dB; other reduction levels are possible. In most decoders, this leads to a reduction in signal-to-noise and dynamic range.

Dolby Digital also provides a "stereo down mixing" feature as a substitute for a dedicated stereo mix. However, many production engineers have admitted that they often have to modify the original 5.1 mixes in order to attain acceptable stereo down mixes. Therefore, the 5.1 mix on many Dolby Digital DVDs may differ from the original master.

5.1 Surround Sound Headphones:

While the traditional method of surround sound described above uses numerous speakers to produce the entire sound field, the surround sound mix is limited to a two-channel stereo mix when using headphones. That is why recent developments in surround sound technology include 5.1 surround sound headphones, to allow you to have the same sound quality and surround sound experience without waking the neighbors or disturbing roommates.

Celebrity Love

There is no doubt that love for some celebrity exists within us all. This isn’t the traditional definition of love but rather defined by an excessive admiration for a famous person whom we will probably never meet. The use of “love” is appropriate here as we who love celebrity tend to exhibit signs of undue influence by those highly visible. Famous people, the non-elected representatives of the human race, have always held some influence over the masses. In the days before mass media, television sets and computers fame was circulated orally, carried by the gossipy nature of social beings. Today, we open our eyes and cannot avoid these people. Of course, in a developed society entertainers are necessary. We laugh and sometimes cry at a quality performance. Our memories are seared with images, movies and songs which have touched us, frightened us and stimulated us. They dramatize the political, the romantic, the good and bad. We see in them the potential for perfection of man or woman as an expression of utopian ideals of love and success.

Yet, have we gone too far? How much influence should they have over us? Our choice of clothes, jewelry and hairstyle, our languages and ideas are often areas that we look toward celebrities to define. If you deny this then you are exceptional; the rest of us are invariably, more susceptible. Our culture has become saturated with celebrity influence. We watch their every move including who they are with and what they do. We absorb their politics and gobble up their quotes. We think about what it may be like to be that beautiful, rich and powerful. Fame is an aphrodisiac or so it seems to the unrecognized. Today we have TomKat(Tom Cruise and Katie Holmes). Yesterday it was Bennifer(Ben Affleck and Jennifer Lopez). Public Interest in these people is frighteningly obsessive in nature. After all, their claim to fame is usually based on pretense or non reality. They are the constant pretenders, illusionists with screens as their canvas.

The entertainment value of a celebrity stretches beyond the screen or stage and they are wholly aware it. We are witness to carefully arranged relationships, sudden sightings in sports arenas and controversial quotes days before a new movie or show opens. They appear on your screen suddenly seemingly not to promote themselves but rather attempting to come across as natural, likable, smart and funny. Sometimes we get a glimpse into what certain celebrities are really like. Unfortunately, it is usually when they do something wrong. Drugs, infidelity and physical assaults are a few areas where celebrities have slipped in their public presentation. Mug shots and unflattering photos of famous people are the currency of entertainment news outlets. Being a celebrity has its drawback in this regard as they are monitored as closely as governmental heads of the biggest nations on earth. Alas, the power of celebrity is here with us to stay. Or is it? Can we teach our children who the chancellor of Germany is before we explain the history of Madonna? If we can’t, America will become a nation of uninformed celebrity worshippers numb to the more important realities of the world.