Achieving Optimum Coverage; The Left/Right Configuration - L-Acoustics dV-DOSC Operator's Manual

3.2 ACHIEVING OPTIMUM COVERAGE

ARRAY 2004 or SOUNDVISION are convenient simulation tools for optimizing the coverage for a
complete system consisting of multiple dV-DOSC arrays and complementary fill systems. Parameters
for each array such as spatial coordinates, azimuth angle (i.e., horizontal panning), number of
enclosures and inter-enclosure angles are entered by the sound designer and individual elements of
the sound design are optimized with respect to the vertical cutview geometry of the audience in
accordance with WST Condition 4.
In the horizontal plane, the displayed isocontours (ARRAY2004) or impact coverage (SOUNDVISION)
should overlap to a certain extent and cover the majority of the audience. For the amount of overlap
see below for a discussion of the tradeoffs between stereo perception versus intelligibility. The
remaining uncovered areas should be covered with fill speakers such as ARCS, KUDO or additional
dV-DOSC arrays. Additional distributed front fill or stereo infill systems using L-ACOUSTICS
MTD108a, MTD112b, MTD115b, 112XT, 115XT or 115XT HiQ loudspeakers are also highly
effective in complementing dV-DOSC system coverage.

3.2.1 THE LEFT/RIGHT CONFIGURATION

Although not the best technical solution, the left/right configuration meets both visual and practical
criteria and is most commonly used. dV-DOSC is a dramatic improvement over conventional systems
but, by nature, the stereo imaging of any left/right system is limited for a large part of the audience and
there are compromises with respect to the consistency of tonal balance in the horizontal plane.
The biggest problem for any left/right system is non-uniformity of tonal balance horizontally. Typically,
an excess of low frequency energy builds up in the middle, accompanied by reduced intelligibility. The
net result is that the system sounds bass-heavy or "thick" in the middle, "harsher or more aggressive"
when directly on-axis with one side of the system, and "thin" offstage. These effects are due to the
path length difference interference effects that are inherent in any left/right system which, in turn,
produce frequency- and position-dependent peaks and dips.
Figure 58c: Main Stage FOH L/R system = 12+12 dV-DOSC, 4+4 SB218 (75 m throw distance); Tent System
FOH L/R = 7+7 dV-DOSC, 3+3 dV-SUB (Toronto Jazz Festival 2002, sound design: M. Vincent)
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dV-DOSC dV-SUB Manual V3.0 June 2005