Most people assume that a great picture is the key to a great home theater. I would argue that the sound is the most important aspect. Many years ago I was given a demonstration that proved this point for me. We were shown a suspense film segment three times over, first with picture and sound together. It was very suspenseful. Next we had just the picture, no sound. Then just the sound, no picture. Everyone in the room, more than 40 of us, agreed that the picture shown alone, without the sound, was not suspenseful. But when we heard the sound, even without the picture, the suspense was there in full.

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Film is all about the communication of emotions. Of the two methods we have for communication — picture and sound — sound is the more effective.

In most cases money and attention is focused on the display, and sound is an afterthought. I believe this is the wrong approach to planning a home theater, whether a dedicated space or a family room system. Proper sound does not require massive speakers that dominate the space. It does require careful speaker placement and matching to the size of the room and image. The main three front speakers should have very similar timbre. Just as you would not use different sounding left and right speakers for stereo, all the front speakers need to be similar in range, efficiency and type. The left and right speakers should be equidistant from the screen. Ideally they should be centered vertically on the image center point. The center should be as close to the image as is practical.

Subwoofers are the most sensitive to placement of all. This can be challenging because the speakers may sound best in a place that is not practical or possible, such as the center of the room. Two smaller subwoofers almost always perform better than a single large one. They will generally perform over a wider seating area when placed on opposite sides of the room. Effects speakers should be higher than the fronts, approximately three feet above the listeners’ heads. As the effect can now contain a full range, they should be as close as possible in quality to the fronts.

There is a long standing discussion in our field as to whether a home theater calls for theater grade or music grade speakers. The speakers’ most important function is to allow dialogue to be heard, which is usually done more effectively with higher efficiency speakers. All public movie theaters, everywhere on the planet, use high efficiency speakers, and our goal is to build a home theater. That does not mean the speakers should not be good for music playback. In fact, they should be chosen with that goal in mind, as well. It is just as important to have the Mozart sound clear and in proper scale as the car chase scene. Therefore, the speaker should be designed for the movie experience but have good music credentials.

When the sound system is carefully chosen and installed, the true magic of home theater shines through.

John Mickelson is a senior systems designer with Audio Video Design, based in Newton, Massachuetts. In addition to being a hi-fi and audio professional with more than 30 years experience, he is also a musician. His opinions and thoughts about sound technology are widely valued, and he is frequently consulted by others in the industry, as well as consumers.