The reason for the emphasis on viewing distance is because if you sit too close to a TV, you will see pixilated images thus distracting your attention from the overall picture, which will in turn deter you from having the desired home theater experience. If you sit too far away, the impact will be lost, as your attention will be divided by objects around the display. Thus there will be no engaging or immersive effect.

The rule of thumb about viewing distance is: it should be three times that of the size of the screen or width of the TV set. Most of us feel comfortable sitting away from the TV set -- at a distance which is between three and five times the width of the screen. The chart below will give you an idea of the minimum and maximum viewing distances for comfortable TV viewing.

Also Read: How to turn your home into a HD theatre