Typical home theater setups are configured with 5.1 channels. The 5 denotes the use of 5 speakers or channels; right front, center, left front, right rear, and a left rear. The.1 indicates a subwoofer for the low-frequency effects. For most home setups, 5.1 channels is adequate, however, some common configurations add an additional two surround channels, called Dolby Digital Plus 7.1. These additional channels include a left side surround and a right side surround. But... The fun does not end here. Newer configurations allow for 9.1 channels, known as Dolby Pro Logic IIz. This configuration adds an additional two front channels, a front left effect speaker and a front right left speaker. The intent is to add the feeling of space and depth to the sound field by placing the effect speakers up high, above the existing front channels.
You don't need to be confused with making a selection on which configuration to choose for your home theater. I love a good setup and put a lot of emphasis on acoustics. However, in order to achieve outstanding results you should not get caught up in all the hype - you don't need 9 channels, in fact you don't even need 7. For most theater's, 5 is perfect.
Going with 5.1 will accomplish the acoustical result you desire and save you money in the process. As you add more channels, the more the demands are placed on your receiver. And if you are concerned about missing out on all the new sounds offered in the latest movies, don't worry...most are still recorded in 5.1; and most importantly, I am confident you won't even notice a difference in adding the extra channels. However, if your intent is to build a very large theater with ceilings higher than 20 feet, you may want to explore 7 or 9 channels. During my design and planning, I decided that I wanted to stick with 5.1 but also keep my options open in the future in case I changed my mind.
Knowing that the studio's are always trying to create and push new sound mediums for the consumer I decided to future proof my room the best I could. I accomplished this by running extra speaker wire, in the 9 channel configuration, and installing PVC conduit in my ceilings so I could quickly and easily run new wire in the future. The extra cost was minimal and I highly recommend it to protect your investment in the future. Plus, if a speaker wire ever fails, etc it can easily be swapped-out.
Another thing I did to compliment my 5.1 setup was to add an extra subwoofer. An extra sub is not necessary, but two are usually better than one for a few reasons. Assuming you are using the same make and models, an additional sub will yield significantly better bass response. The sounds will be smooth and more evenly dispersed and the listening area will be wider. The quality of the sound will extend to all of your seating areas and you'll have a very hard time determining the source of the low frequencies; often with a single sub the bass may sound good from one seat and lumpy from another. Assuming proper placement, one sub is good but two are even better!
Bottom line, when designing your home theater all you need is a 5 channel setup; don't get caught up by all the hype on adding extra, unnecessary channels. If your receiver supports the use of two subwoofers, go ahead and add an extra. And last but not least, don't forget to future proof your room by adding some extra wiring and conduits.
