Martin Audio Wavefront W8CT, Application Manual

Page: 127 / 247

In the following example, listeners over a wide central area will hear a warm bass
note rich in harmonics whereas those around the sides (in line with the subwoofers at
90º) will hear less of the fundamental but more of the harmonics whose full
wavelengths coincide with the subwoofer spacing.
Listeners in the 60º zone will hear the note at a reduced level and may be more aware
of room reverberation because the direct-to-reverberation ratio would be poorer for
that note. Other notes would give different effects.
In practice, these peaks and troughs can be smoothed out with additional fill systems.
4.11 Electronic steering
It is possible to “aim” ground-stacks towards distant raked seating or balconies or
away from problematic areas by electronically “tilting” the system using multi-
channel digital delay lines.
The illustration below shows the basic schematic plus the staircase effect** (greyed
out) produced by the progressive increase in drive delay from bottom to top.
**Important Note:
The staggered stack (shown greyed out) illustrates the effect of electronic
steering.
For safety reasons, never try to tilt or stagger a real subwoofer stack.
All material © 2007. Martin Audio Ltd. Subject to change without notice.