When you set up surround sound in an imperfect acoustic environment like a family room, there are 4 ingredients for creating that feeling like you're in the movie - wide sound field, center speaker placement, the motion-sound connection, and subwoofer placement.
First, we need a wide sound field
. We want the right and left speakers further apart. We do not just want to flank them next to TV. When you are watching television or movies, most motion goes left to right. While everyone talks about famous surround sound scenes that utilize the back speakers, such as Top Gun, The Matrix, Mr. and Mrs. Smith, etc., the truth is that most motion on the screen moves left to right. A wide sound field exaggerates this motion to make you feel like you are in the movie, not just watching it.
Secondly, we want the dialogue audio to be connected to the video, which is where center speaker placement
comes into play. We want the center speaker located above or below the screen usually within 16 inches. Builders will wire many track homes for center speakers in-ceiling, but unless your TV is mounted high, like over a fireplace, this is going to create a disconnect where when you look at someone’s lips in the movie you are watching. When you hear dialogue, you are going to know it is coming from the ceiling and not seem real.
Thirdly, the tweeters need to aim to the seating area to create the motion-sound connection
. Generally, low frequency sounds are less directional than high frequency sounds. If you imagine the inside of a speaker, there is a woofer aka “the big speaker” which handles bass and mid-range. Then there are wide dispersion speakers aka “the small speakers”. Finally, the tweeter, which handles high frequency sounds is a narrow dispersion speaker, think of it like a flashlight beam coming out of the speaker. The high frequency sound is how our ears track motion. Sounds such as, bullet ricochets, glass breaking, or crunching of dry leaves, allow us to add realism to the motion we see on the screen.
Lastly, subwoofer placement
is a lot more simple. The purpose of the subwoofer is to handle deep bass. Subwoofers are just the opposite of a tweeter. Frequencies below 80 HZ become monosonic, which means that even if the subwoofer is next to your chair, you will think it is coming out of your other speaker. This is ideal. Since they are non-directional, we can locate the subwoofer in the room and focus more on the settings as well as hiding it (for aesthetic reasons) and not have to worry about the acoustic impact.