Surround Sound Systems

There is nothing more depressing than when you turn on that big, brand new widescreen TV and get low, inferior sound. This is where surround sound excels. Surround sound produces pure, clear music and dialogue that gives an almost eerie "you are there" sensation. There's a little audiophile in everyone and your audiophile is screaming "surround sound!" Where to begin?

Defining Surround Sound

Surround sound refers to digital formats that use multiple audio tracks driven through a surround sound-capable audio system to produce an immersive sound experience.

At minimum, a surround sound system requires five speakers each placed in a set relationship to the listener. For example, the two front speakers in a surround system placed in front of the listener deliver the majority of the sound. Two surround speakers are placed to the side (above head level) of the listener and carry ambient noise such as footsteps or rain falling. A final, center speaker sits at the TV and carries dialogue tracks. In addition to the main speakers, a sub-woofer designed to reproduce bass effects may be used. The sub-woofer does not rely on direction to deliver sound, so it can be placed almost anywhere in your home theater space.

Surround Sound Formats: Dolby, DTS, Pro-Logic

Dolby DigitalTM is the standard for DVD and is used by digital, HDTV, and most pay-per-view broadcasts. Dolby is often called 5.1 in reference to the five tracks available for audio and the .1 track available for bass effects.

DTS Digital SurroundTM is a competitor of Dolby Digital. DTS provides higher data transfer rates than Dolby, which is the primary difference between the two. DTS may produce better quality, but it is hard to find DVDs or broadcasts content that employs it.

Dolby Surround Pro-LogicTM is a pared-down version of Dolby Digital designed for VHS and analog stereo broadcasts. Pro-Logic is still very much in use.

Other Surround Sound Formats

Surround sound formats like Dolby Digital EXTM, THX Surround EXTM and DTS Extended SurroundTM have emerged. These 7.1 channel surround formats provide back channels for sound effects that appear to come from behind a listener and require the use of two back speakers.

Surround Sound: Equipment You Will Need

There are a number of considerations in selecting surround sound equipment. Most audiophiles will want to buy equipment that will produce both theater sound and music well. If you just like to watch TV and movies, speaker sensitivity and impedance won't be a high priority.

A typical surround sound system consists of:

  • Five or seven speakers
  • A sub-woofer
  • An Audio/Video (AV) receiver or separate preamplifier/processor amplifier receiver components.

High-end users and audiophiles are more likely to want separates, but AV receivers are an excellent budget-stretching alternative. Both separates and AV receivers can produce excellent sound.

For the receiver portion of your system, pay attention to inputs and outputs. Always think in terms of future expansion. Models with coaxial and optical digital connections offer the most flexibility.

Spatial Considerations When Buying Surround Sound Systems

There are two theories about buying surround sound. Theory 1 says spend as much on your surround sound equipment as on your TV and DVD combined. Theory 2 says find the system that fits in your home theater space-cost is secondary.

While it is often incorrect to assume that a higher price tag means better quality, it is rarely wrong to propose that a surround system be well matched to its environment. In fact, the most important quality of any surround sound system is how it sounds in your home.