It may sound confusing, but the concept is pretty simple and the results are fantastic. To explain multi-channel audio, we need to travel back in time a bit to when for many of us the two-channel stereo system was the best music source in the house. It gave us the basic left and right speaker and we thought it sounded awesome, and for the most part it did its’ job well. If we had a party, we’d unplug it, pick it up and plonk it on a dining table or somewhere near where the guests were congregating so we could point the speakers within earshot. Simple two channel stereos are still around, and are pretty common in bedrooms, kitchens, garages or any place you are looking for a more portable solution. Often these units are dual purpose as mp3/iPod docks and chargers, which can make them convenient. Multi-Channel Surround Sound is a completely different experience.
It refers to the use of multiple audio tracks to reconstruct sound using a multi-speaker sound system. It has at least four, and often up to seven independent audio channels or speakers. It typically boasts a front left and right speaker, a front centre speaker plus two surround speakers to be positioned at the sides of the room. Some systems include additional rear and/or side speakers to enhance the surround sound field. A subwoofer is almost certainly essential in any surround sound set up, as it is the speaker responsible for those awesome low bass notes, of which cannot be truly replicated by any of the other speakers (read our blog about subwoofers). With its’ beginnings in the 1970’s, multi-channel sound is also known as 5.1, 6.1 or 7.1 channel sound. This is certainly not the limit of speakers, as more speakers can certainly be added to intensify the “Surround Sound” experience.
So what’s so good about all those extra speakers?
When a sound engineer records the audio for an album or a movie, they specifically and purposefully designate the channel (speaker) that they would like the audience to hear each signal (sound) from. For example in an action scene from a movie, they may begin the car chase at the front left speaker, travel through the centre to the front right, then follow through the side then rear speakers as the cars crash together. Simultaneously character dialogue will be moving around various speakers. The engineers designate the specific sounds and at what specific time they are to be sent to the various channels in your system. If you are listening to this same audio through a two-channel stereo system, the soundtrack will be combined and expressed as best it can through the two available speakers. Because you are unable to position the speakers around you, you will not experience the true intention of the recording.
This is also the same for albums. When the artist’s engineer lays down the tracks, they will direct certain instruments and vocals to be expressed from particular channels to give the listener a more encompassing experience. When played on a two-channel speaker set-up, the results can often be described as flat or tinny, because the two available speakers must combine the multi-channel signal into left and right only.
Multi-channel audio allows the listener to experience the sound the way the artist intended it to be heard, and with a stronger sense of involvement. This doesn’t mean that you should get rid of your favourite two-channel stereo, because they definitely have a place, however if you are thinking about plugging something into your tv, consider a system which offers multi-channel or surround sound. Your ears will thank you.
