L-Acoustics V-DOSC, Руководство оператора

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L-ACOUSTICS V-DOSC Manual Version 4 6/29/2005 Page 74 of 158
H-ISOCONT SHEET
The H-ISOCONT sheet is used to check horizontal coverage by mapping a projection of the
horizontal isocontour of the defined V-DOSC and dV-DOSC arrays onto the user-defined audience
area. By matching horizontal coverage to the audience area, H-ISOCONT can be used to check array
placement / aiming and stereo imaging, as well as to determine whether offstage fill, front fill or center
cluster arrays are required. Two audience areas can be defined and the coverage of up to four arrays
displayed (4 x V-DOSC, 4 x dV-DOSC). Calculation assumptions include: 3 dB SPL reduction with
doubling of distance (i.e., arrays have been designed for constant impact spacing using their respective
Cutview sheets); anechoic or reflection-free conditions (direct sound only).
Input Data
Just as for cutview sheets, input data cells are in black and results are displayed in red. To define a plan
view of the audience area, the user inputs x (range) and y (distance off-centre) coordinates in the
Contour 1 and Contour 2 cells. A mirror image drawing scheme is used (so that only half the room
needs to be defined) and after coordinates are entered, the display of the audience area is updated
when the SCALING button is pressed. It is only necessary to define Contour 1, however, Contour 2 is
useful to represent balconies, stage thrusts, proscenium opening, FOH location etc.
When V-DOSC and dV-DOSC arrays are defined (in V-ARRAY1,2 and dV-ARRAY1,2 Cutview sheets
respectively), they are automatically displayed in the H-ISOCONT sheet with the x location of each
array referenced to the defined Offset Distance taken from each arrays' respective Cutview sheet.
The parameter ''Isocontour at Distance (m)'' refers to the throw distance for the top enclosure of the
respective array and is given relative to the defined Offset Distance.
The user then enters the ''Console Output Signal (dBu)'' for each array, i.e., output level of the mixing
desk (0 VU = +4 dBu) and the Continuous A-weighted SPL is tabulated, corresponding to the SPL
that would be obtained along the isocontour for each array. The Console Output Signal can be
increased until the amount of headroom available in the system goes to zero and the user has an
indication as to the peak A-weighted SPL that will be available along the isocontour. Further increases
in the Console Output Signal will produce a CLIP indication reflecting amplifier clip.
The user can also define the y coordinates for each array (off-center distance) and the azimuth angle in
degrees (i.e., aiming or panning angle of the array). Note: to simulate a centre cluster, simply set ''Y
location'' equal to zero.
Optimization Procedure
Typically, the optimization procedure begins by using the V-ARRAY1, V-ARRAY2, dV-ARRAY1 or dV-
ARRAY2 cutview sheets to determine the number of array enclosures, inter-enclosure angles, etc. H-
ISOCONT is then used for adjustment of array separation and azimuth panning angles to ensure
adequate audience coverage and stereo imaging at a desired A-weighted SPL in order to match
coverage to the audience area. In some cases, when horizontal coverage is an important design issue,
simulation can start with the H-ISOCONT sheet first in order to predetermine the 0 and 45 degree
axes prior to more detailed cutview simulation.
Output Data
Output data is directly displayed as the projection of the horizontal isocontour on the defined
audience area. The A-weighted SPL and amount of headroom in the system are given for each array.
Note that the displayed isocontour for each array is terminated in a line that is referenced to where
coverage starts for the bottom enclosure. Therefore, H-ISOCONT gives a direct indication as to the
areas where coverage is lacking and offstage fill, center fill or delay clusters are required. The overlap
between L, R arrays illustrates which portions of the audience will experience stereo imaging.
Note: It is not possible to simulate the transition between dV-DOSC to V-DOSC isocontours in ARRAY 2004
when dV-DOSC is used for downfill or upfill in conjunction with V-DOSC. In order to simulate this transition,
SOUNDVISION is recommended.