Home Cinema Surround Sound - Why Would You Want a Multi-Channel Surround Sound Setup?

If you've looked into installing your own home cinema surround sound system then you will most likely have come across the different options when it comes to the number of surround sound channels. Should you go for a 5.1 setup which gives you 2 surround channels or maybe a 7.1 setup which gives you 4 surround channels?

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