Surround Sound is a description of an audio system with multiple audio channels in which the sound is specifically designed to surround the listener. (see our blog explaining Surround Sound) Surround sound engages the listener into a more realistic experience. The bullet shot from the gun can be heard whizzing by your left ear, as the soundtrack is specially encoded (mixed) to express individual sounds from separate speakers.
5.1-channel sound is simplest set-up of surround sound. This includes a centre speaker to project the voices from your soundtrack, which is positioned above or below your screen. A pair of left and right front speakers give you the big movie score and sound effects. A pair of rear left and right surround speakers give you added effects with each speaker playing a unique signal. The final piece is the subwoofer, which plays just the low bass notes. So the "5" means the five speakers and the ".1" means the subwoofer. It's a very effective, immersive form of surround sound, and just about every new DVD movie with a multichannel soundtrack provides a 5.1 surround option.
6.1 channel surround sound, gains you an extra rear centre surround speaker. The original surrounds would still sit to the rear left and right, while the extra rear surround sits directly behind you. If playing a true 6.1 soundtrack, this rear centre speaker plays its own unique channel of sound. Because movies haven’t been mixed in 6.1 for about 10 years you will find that your 6.1 receiver, when watching 5.1 movies, will copy audio from the left and right rear speakers and express the signal through the sixth speaker.
7.1-channel sound adds one more rear speaker. An increasing quantity of Blu ray discs are now encoded for seven individual channels of sound as well as a subwoofer. If you’re watching a movie that is encoded for 5.1 or 6.1 surround sound, your two rear centre speakers will be playing a combination of the music and effects that are also coming from your left and right rear speakers. When watching movies encoded for 6.1, both your rear centre speakers will express identical signals.
You may wonder why it’s worth even bothering with anything above 5.1. Well, you will find that by including the extra 2 speakers, you will be even more immersed in your movie, and keep in mind that future proofing is about preparing for technology before it’s common. It really is only a matter of time before 7.1 is the standard. Why not jump on board now?
