"Hi-Fi" and stereo were the big things for audio enthusiasts decades ago. Some people even bought vinyl records of sound effects just to marvel at the fidelity and stereo effects. Quadraphonic sound was tried for a while
(prHWY.com) November 7, 2012 - Charleston, AZ -- but systems were expensive and recording and media required 2 additional channels. In the last decade digital audio has made even more sophisticated systems not only possible but also affordable.
Surround Sound, Dolby, and THX
Stereo uses 2 recorded sound channels to feed a left speaker and a right speaker, roughly corresponding to our left and right ears. Surround sound processes additional channels to enrich the audio experience with additional speakers. There's several types of surround sound. The first uses a fixed listener location for a 3-dimensional audio effect. Unfortunately this also means there's a single "sweet spot" where the effect works best. Other types use speakers behind the listeners for an audience-wide experience. Each speaker feed is called a channel.
Audio processing from Dolby Laboratories began way back in the 1960s with noise reduction. Dolby processing has evolved to multi-channel surround-sound processing through a succession of small steps. One of the most recent is Dolby TruHD. This provides loss-less encoding (no information lost, no noise added) of 8 or more channels.
You may have read about receivers boasting about THX. THX isn't actually a recording, encoding, or surround sound technology. It's actually a quality standard and certification system. Originally used for movie theaters, it "guarantees" high-quality multi-channel sound.
5.1 Channel Systems
The most common arrangement today uses 6 speakers, and is referred to as 5.1 channels. The ".1" channel is for a sub-woofer dedicated to powerful very low frequencies. A good sub-woofer is especially
https://vimeo.com/53052540 important for movie and video game special effects. Two of the remaining speakers are the standard stereo speakers. Another pair is also stereo, but these "rear" speakers are placed behind the listeners. So you literally are surrounded by sound. The final speaker is a middle speaker, placed between the front stereo pair. Ideally, it's mounted fairly high to provide a broad sound experience.
7.2 Channel Systems
Add 3 more speakers and you have a 7.2 channel system. Many current receivers can only handle 5.1, so be sure to choose one that can handle the 9 speakers if you want to go with this arrangement.
The ".2" speakers are two sub-woofers, making your deep bass truly stereo. The remaining pair can be used in several ways. The best sound comes from placing them in front above the main stereo pair. Here you'd place the middle speaker a bit lower. You can also place them further to the left and right of the main stereo speakers. Finally, you can use them as remote speakers in an entirely different room.
Wrapping Up
These may sound like complicated systems, but each channel and speaker has its purpose and place. They're really not that difficult to set up. You may have to be clever in running wires to the rear speakers so that they're not too visible, but wireless speakers are available if this is too much trouble. Either way, it's well worth the effort. Installing a home theater surround sound system will raise your music listening, movie watching, and even video gaming to a whole new level.
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