Martin Audio Wavefront W8CT, Application Manual

Page: 112 / 247

Vertical Boundary effects
A solid floor will act as a reflector. This will cause a vertical stack to perform as if it
were double the length, giving a useful low frequency boost accompanied by a
narrower, more complex polar response.
For instance, an 8 high ground-based stack of WSXs will act like the top half of a 16
high stack.
At 80Hz its smoothest vertical coverage will be from the floor to its own height
(4.6m) + 16.5º. It will, therefore, cover seats 19m above floor level at a distance of
50m and 34m above floor level at 100m.
It is possible to reach higher seating areas whilst retaining the long throw
characteristics of a tall vertical stack by electronically “tilting” the system - see
Section 4.11 .
Note that flexible floors may actually absorb sound at some frequencies so the
situation isn’t always so simple in practice.
Horizontal - 6dB coverage
The following table gives the approximate horizontal coverage angles of typical WSX
arrays - ignoring boundary effects.
WSXs Wide Horizontal coverage
(on sides) 40Hz 80Hz 160Hz
2 Wide Wide 75º
4 Wide 75º 35º
8 75º 35º 17º
16 35º 17º 9º
All material © 2007. Martin Audio Ltd. Subject to change without notice.