Constant Curvature Dv-Dosc Array; Variable Curvature Dv-Dosc Array; Concave Curvature Dv-Dosc Array - L-Acoustics dV-DOSC Operator's Manual

Constant Curvature dV-DOSC Array

For a constant curvature array, the vertical directivity is nominally (N-1) x A° where N is the number
of enclosures in the array and A° is the constant angle between each adjacent enclosure. Therefore, a
curved array of 9 dV-DOSC enclosures can provide a maximum vertical coverage of 8 x 7.5° = 60°
while still satisfying WST criteria.
The constant curvature array is the simplest type of convex curvature dV-DOSC array. This
configuration should only be used for smaller sized arrays or when the geometry of the audience is
unknown. Since an array of constant curvature radiates the same amount of energy in all directions
over the nominal vertical coverage angle, this type of array is of practical use only when the entire
audience is sitting at the same distance from the array.
However, in most venues, a dV-DOSC array will have to cover an audience sitting at varying distances
from the array and a constant curvature array would produce excessive SPLs in the first rows
compared to the remote audience. Therefore, a constant angular spacing between enclosures is
generally not useful for most applications. If this configuration is used, the gain of the amplifiers
powering the high frequency section of the lower dV-DOSC enclosures might need to be
progressively reduced (however, such attenuation results in a global loss of energy).

Variable Curvature dV-DOSC Array

Since individual dV-DOSC enclosures radiate a flat, isophasic wavefront it is possible to focus energy in
a given direction and increase the SPL by reducing the angles between enclosures. Conversely, by
increasing the angle between enclosures (up to a maximum of 7.5°) it is possible to lower the SPL in
another direction. This is the basic principle that allows energy to be distributed uniformly throughout
the audience and variable curvature arrays are used to adapt both the coverage of the system and the
SPL distribution to match the specific audience geometry according to WST Condition #4.
Shaping the VERTICAL ISOCONTOUR is the key to Wavefront Sculpture Technology.

Concave Curvature dV-DOSC Array

If dV-ANGLEN rear angle bars are selected, concave or negative curvature arrays can be constructed.
A flat array is obtained using the minimum hole position on dV-ANGLEN and the array becomes
progressively concave as hole positions with greater spacing are selected. Experimentation into the
use of negative curvature arrays is ongoing and it is thought that such arrays will be useful for long
throw applications and for acoustic holography effects where it is possible to create a virtual acoustic
source by focussing sound at a point in space. The sound will then appear to emanate from this focal
line - not from the array itself - allowing for interesting sound design possibilities.
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dV-DOSC dV-SUB Manual V3.0 June 2005