When it comes to home theatre speaker placement and six speaker surround sound systems its important to understand a few points about how we hear and perceive sound. The typical human is able to hear sounds in the range from 20hz to a bout 20khz. Human speech usually falls into a range from about 1khz to 4khz. Our ears can tell the direction of high frequency sound far better than they can determine where low frequency sounds come from. From this we can see why home theatre speaker placement is important:
Subwoofer
The sub woofer only reproduces low frequencies. Since its difficult for us to determine the direction of lower frequencies a single subwoofer can handle all of the low frequency sounds without really affecting our listening experience. This also allows the sub woofer to be placed much anywhere in the listening room.
Center Mid Range Speaker
The center channel speakers handle most of the mid frequency range of sound. Ths covers the range of human speech, and as voices come from in front of us on our home theatre, speaker placement obviously should be also in front of us.
Satellite Speakers
The four sattelite speakers, front left and right, and rear left and right reproduce primarily high frequencies. As these are the frequencies that enable us to determine the direction of sound, placing these speakers well out from the center speaker enhances the effect of positional sound. Since these speakers only handle the higher frequencies the satellite speakers can be quite small and still be totally efective .
With a solid understanding of home theatre speaker placement and how speaker systems work its easy to see why they are so much more effective that the large speaker boxes of days gone. By applying todays technology you can get a far better sound from the smaller speaker systems. This next brings us to home theatre room design...