Cardioid Mode; Description - Acoustics SB18 Manuel D'utilisation

7.3

CARDIOID mode

7.3.1

Description

The CARDIOID mode consists in arraying four SB18 subwoofers with three of them having front faces turned towards
the audience and one of them turned towards the rear. Such an arrangement produces a rear and/or side SPL rejection
in the coverage pattern. The associated cardioid presets are available in both LA4 and LA8 PRESET LIBRARIES.
The basic arrays contain four enclosures. Several basic arrays can then be put together to form bigger ones. The
recommended basic cardioid arrays are the "vertical", "block", "on-end", and "horizontal" ones, as shown in Figure 10.
They feature the following properties:
•
All arrays provide rear rejection.
•
The "vertical" array provides symmetric coverage pattern in the horizontal plane.
•
The "block", "on-end", and "horizontal" arrays provide asymmetric coverage pattern in the horizontal plane
by generating additional rejection to the side of the reversed subwoofer.
If two (or more) basic arrays are intended to be used in close proximity from each other it is
recommended to set the distance at 0 (as shown in Figure 12).
If it is not possible, the maximum distance between two acoustic centers is 2.8 m in the
IMPORTANT
32-60 Hz frequency bandwidth, and 1.7 m in the 32-100 Hz bandwidth.
VERTICAL
SB18_UM_ML_1-2
BLOCK
HORIZONTAL
Figure 10: SB18 basic cardioid arrays in CARDIOID mode
w w w . l - a c o u s t i c s . c o m
ON-END
15 en 15 15 15
EN