What is Surround Sound System?
Surround Sound System - Explained
Digital Surround sound is the main feature of home theater that is behind its reproduction of amazing sound effects. In a movie theater enabled with DTS technology, you would have often experienced sound coming towards you from different directions. Various sounds, dialogue and sound effects do not come from just left or right or front of you, but all around you depending on the scene. This is because, the original sound of a movie is split into many channels and sent to various speakers located on all the sides of a movie theatre. This makes for the amazing sound experience. Home theatre, a replica of a movie theater, uses same techniques and surround sound audio format to produce similar effects
Analog Surround sound
Surround Sound concept has its origin in analog surround sound or 4-2-4 audio processing which is also known as stereophonic sound system. It has been the basic surround sound format until Dolby developed digital surround formats like Dolby Digital and Dolby Pro Logic. In the standard stereo sound system, the sound decoder receives the sound signals from two audio channels and processes them and sends them to the speakers usually located on either side.
Digital Surround Sound
Home theater uses digital surround sound decoder and surround sound formats developed by Dolby Laboratories and Digital Theater Systems (DTS). As most home theaters support both Dolby and DTS surround sound formats, it is really not a headache for you. However, it can be, when it comes to choosing the number of speakers you want to use as you have to consider your budgetary limits also. Currently, Dolby 5.1 surround is popular and other options 6.1 and 7.1 are also available.
How Digital Surround Sound works?
The A/V Receiver in a home theater splits the audio information into different sound channels and the decoder sends each sound channel to the appropriate speaker. There will be five or more speakers placed at front, at right, at left and on the rear side of the listener. In addition, Surround sound has a special speaker, subwoofer that provides bass audio effects.
It is quite interesting to see how the speakers handle different audio information. We hear all the dialogue from the centre front speaker and the left & right front speakers provide the three dimensional effect when the characters move and give the impression that sound comes from their direction. The rear speakers give out other sounds that are happening in the movie - the rustling of leaves, rain, chirping of birds etc.
There are various surround sound formats and each differs from other in terms of number of speakers used:
(Note: You need to use the right kind of video source to get the best theatrical experience by using the following speaker placement)
Dolby 5.1 Surround sound setup
In this setup, there are five speakers and one subwoofer used to provide surround sound effects. Here is how you can setup the speakers and subwoofer:
- One Centre Front speaker in front you. It can be placed over the TV or in a cabinet below the TV.
- Two Centre Front speakers on either side of the TV with slightly tilted towards the listener.
- Two Rear speakers placed behind the listener on each side at an angle facing the listener.
- Subwoofer can be placed on left or right side of the listener.
Dolby 6.1 Surround sound setup
Dolby 6.1 sound setup has an additional speaker which is placed right behind the listener. The placement of the Centre speaker and two centre front speakers do not differ from Dolby 5.1 setup.
However, the left and right speakers are placed directly on either side of the listener. Subwoofer can be placed on right or left of the listener.
Dolby 7.1 Surround sound setup
Dolby 7.1 uses seven speakers and a subwoofer and provides the best surround sound features. Here, there are separate sound channels for left and right rear speakers so the sound effects just pour out from all directions.
The placement of the Centre speaker and two centre front speakers and subwoofer do not vary from Dolby 5.1 or 6.1. The left and right speakers are placed directly on either side like Dolby 6.1 setup.
Two rear speakers are kept behind the listener, tilted at an angle facing towards the listener.
