The Surround Speakers
dipolar surround placement
phase-induced irregularities at the crossover frequency of 80 Hz.) Of these two guidelines, the first is usually more significant sonically, as it tends to minimize the audibility of the room’s modes. Avoid corner placement, as this typically in- creases bass quantity at the expense of bass quality (by stimulating every room mode supported by the room).
The actual number of subwoofers used in an installation will depend on both the size of the room and on the manufacturer’s design. Of course, having multiple subwoofers enhances the maximum level at which they will play. Additionally, there is an advantage to having more than one subwoofer in the room. Smoother bass may be obtained by placing two subwoofers asymmetrically in the room, since different sets of room modes would then be excited by each. The peaks of one set of room modes could offset the valleys of the other one to some degree.
Ideally, the rear speakers will create a diffuse,
If
L sur | sub |
| L |
| C |
R sur | R |
|
If more traditional speakers are used, they should be placed such that their out- put is scattered across the rear of the room. (See diagram, next page.) Often, the best results will be obtained by placing them relatively high and slightly behind the listener,
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