Dolby Laboratories is known for it’s various digital audio systems. Almost every home theater system or personal audio system has the little Dolby Digital logo on it.
Founded by Ray Dolby in 1965, Dolby has become the leading company in consumer digital audio standards. The most common surround sound systems are:
Most people don’t understand what these numbers mean. It’s quite simple, really.
X = Number of simple speakers at ear level (or a little above ear level)
Y = Number of sub-woofers (usually 1)
Z = Number of height speakers at ceiling level
For example; 5.1.4 means 5 simple speakers, 1 sub-woofer and 4 ceiling speakers.
The ‘simple’ speakers are usually arranged around the listener. For example, the 5 speakers in 5.1, 5.1.2 and 5.1.4 are:
- Front Left
- Front Right
- Back Left
- Back Right
The only exception is 9.1, in which 2 extra speakers are placed 3 feet above the front left and right speakers to provide a third dimension to the audio in height. However these are not considered as ceiling or height speakers and are included in the simple ones.
The systems with height speakers are said to be a part of the Atmos systems. These systems were introduced in April 2012. The first movie to use Dolby Atmos was ‘Brave’.