AC-3 or Dolby Digital
Digital surround processing and the most current format for surround processing. The unique feature of AC-3 is that all the audio channels are discrete, so there is a clearer sense of direction and a better localization of sound effects and dialog.



Audio/video Preamps And Receivers
This is the heart of the system and should be chosen carefully. Many of the mid-range receivers are AC-3 capable allowing for a future upgrade.



Digital Theater Systems or DTS
A technology invented to transform existing "home theater" systems into six discrete channels of exceptionally clear, better-than-compact disc, digital audio performance.



Dolby Pro Logic
Surround audio system is the most basic surround sound. The higher grade systems use THX or Dolby Digital technology.



Dolby Pro Logic
Surround audio system is the most basic surround sound. The higher grade systems use THX or Dolby Digital technology.



Front Speakers
The three speakers that create the forward sound field should be similar if not exactly the same. Energy AC300HGB, Mission 70 Series and the M and K LCR75 are good examples of a typical front channel array. The objective is to maintain a smooth transition from each speaker to the next. This is accomplished by using three similar, or "timbre matched" speakers across the front left, center and front right channels



Multi-Zone System
A whole-house audio system that can play different audio sources in different areas at one time is a "multi-zone system." New products have recently made multi-zone systems easier to afford and simpler to install.



Powered Subwoofer
The subwoofer allows the use of much smaller satellite or even bookshelf speakers in the front which requires much less space. Subwoofers do not take any power from your receiver or amplifier letting it concentrate all its wattage on the satellite speakers. Bigger is not necessarily better in subwoofers. The smaller size means the speaker will respond quicker and will often give a more precise and accurate sound. Also remember that with bass you are basically moving air, so with a very large room you may need two or more to get that chest pounding effect.



Pro Logic
Theater sound processing developed by Dolby Labs which essentially adds a center channel used primarily for dialog and action at center screen.



Single-zone system
A whole-house audio system where all speaker pairs, at any given time, play the same source technically has a single zone. A single-zone system is easier to set up and less expensive than a multi-zone system.



Speaker Pair
A speaker pair usually serves one room. A room is part of a "zone."



Surround Speakers
When at all possible you'll want to use dipole/bipole surround speakers. They are bi-directional and they create a more diffuse sound field, an efficient coverage of a 180 degree listening angle.



System
A whole-house audio "system" includes dedicated audio source equipment, audio distribution and amplification equipment, infrared remote control distribution equipment, wire and cabling, speakers, and controls.



THX
In 1980, George Lucas set out to develop and implement a set of quality control criteria for theaters. His goal was to ensure that his films, as well as those of other filmmakers, would be accurately reproduced for moviegoers for whom sound was an important part of their overall film enjoyment. THX systems were installed in two theatres for the premiere of RETURN OF THE JEDI. Today, more than 2000 theatres and dubbing stages around the world meet THX requirements.



Zone
A whole-house audio "zone" is one or more speaker pairs that, at any given time, will play the same audio source. A whole house audio system may have only one zone (see single-zone system), or it may have several zones (see multi-zone system).